Phase 1 — Engineering Validation

A Proposal for
HelixFlo

This proposal sets out Phase 1 of the HelixFlo development programme: an independent engineering audit and supplier engagement workstream that maps the pathway from the current design stage through to qualified mass production. Status: provisional, subject to the Engineering Review Call set out in Section 10.

4–6 Weeks

USD $7,500

Provisional — Pending Engineering Review Call

01 — Background

HelixFlo & Nguyen Mechanical Systems

Nguyen Mechanical Systems is a California-based product business founded by Hoang (Wynn) Nguyen, a mechanical engineer with 25 years of medical device and Class III implant manufacturing experience and a track record of commercialising premium engineered products. HelixFlo is the company's first consumer product platform: a modular, premium shower filtration and hygiene system positioned distinctly from the commodity shower filter category.

The platform consists of three primary sub-assemblies. A reusable adapter that interfaces with the standard half-inch NPT residential shower pipe and is intended to remain in place as permanent infrastructure. A disposable filter cartridge with an internal helical flow geometry, multi-layer media including KDF and activated carbon, and an injection-moulded housing, replaced on an approximate three-to-six-month cycle. A reusable rain shower head, planned in round and square rainfall geometries with future variants, with removable nozzles engineered for routine cleaning and maintenance.

Architectural design is reported as 95 per cent complete. CAD (STEP), 2D engineering drawings with tolerances, and a bill of material are produced and will be shared with the Shield Works R&D team in advance of project confirmation. Wynn has explicitly stated that the design is locked at the functional level and that the remaining work is the cosmetic refinement and the housing connection mechanism (bayonet or quarter-turn), to be optimised with manufacturing partner input.

The commercial model is razor-and-blade: the housing system runs at a low or zero margin, with the disposable cartridge providing recurring revenue. Premium positioning, salesperson and influencer channels are already in place pending the first marketing samples.

C2W and Shield Works have been engaged to assess the current design independently, provide an expert manufacturing and engineering perspective across the three sub-assemblies, and map the pathway from the current design stage through to qualified mass production. This proposal covers Phase 1 of that programme, titled Engineering Validation, following the NDA already in place between our teams and the discovery call held with Wynn earlier this month.

This proposal is marked provisional. The scope and fee set out below are firm. A dedicated Engineering Review Call between Shield Works R&D and the Nguyen Mechanical Systems team is proposed as a no-cost gate before project confirmation, to align the Phase 1 emphasis against Wynn's real technical priorities, principally the cartridge manufacturability and sub-assembly architecture across the three components. See Section 10 for the suggested sequence.

02 — Preliminary Read

Our Preliminary Read on the Product

Ahead of Phase 1 engagement, our team has completed an initial review of the brief, the discovery call notes, and the architectural description of the three sub-assemblies. CAD and BOM files will be reviewed on receipt. The following is not the full Phase 1 output, but it is the position from which our engineering work will start. Sharing it now signals where our focus will be.

Where quality, cost, and timeline are actually won or lost. In our view, five engineering areas drive most of how a premium modular shower filtration platform of this type performs, costs, and scales. These are the areas our Phase 1 engineering work will prioritise.

Cartridge manufacturability and the internal helical flow geometry

This is the central technical question on the product and is set up as a standalone engineering workstream. The cartridge is the disposable consumable that carries the recurring revenue, the internal helical geometry is the engineering feature that differentiates the product, and the moulding of complex internal geometry is the area where cost, manufacturability, and design intent must be reconciled. Parting line strategy, draft angles, undercuts, side action requirements, ejection mechanics, and water-tight sealing at the cartridge interface are the questions that determine tooling investment and per-unit cost. Wynn has designed the helical geometry; our Phase 1 work will quantify how to manufacture it reliably and economically at scale.

Reusable adapter material and process selection

The adapter is the permanent infrastructure of the platform and carries the cosmetic burden of the system. The material decision (anodised aluminium, plated brass, stainless steel, or engineered polymer) interacts with the manufacturing process (CNC machining versus die-casting with post-machining), the threading durability under repeated installs, the sealing geometry against the cartridge, and the cosmetic finish path. Phase 1 will produce a ranked recommendation based on cost, finish quality, durability under repeated use, and supply chain reliability.

Reusable rain shower head architecture and removable nozzle design

Multiple rainfall geometries are planned (round, square, with future variants), and the differentiator versus standard shower products is the removable, cleanable nozzle. The material choice (copper, copper-nickel, stainless steel, or hybrid metal and polymer) interacts with the manufacturing route, the nozzle retention mechanism, and the cosmetic finish. The variant strategy is a tooling investment question: which geometry is tooled first, which is staged, and which sub-assemblies are genuinely shared across variants.

Cosmetic finishing across all three sub-assemblies

Premium positioning depends on the surface finish. Sandblasting, anodising, electroplating, and polishing are each specific processes with their own cost, lead time, and quality implications. Phase 1 will identify the right finishing path for each sub-assembly and provide indicative finishing cost as part of the unit cost build, delivered through our qualified supply chain as part of the all-in unit cost.

Filter media supply qualification

Wynn has named supplier sources for the KDF (85/75/65) and activated carbon media. Phase 1 will engage those suppliers to confirm specification, MOQ, lead time, and consistency, and will set out the incoming quality control criteria that protect product performance from media-grade variability. Media qualification is the supply-chain side of the cartridge programme and is treated as part of the cartridge workstream.

Variant Strategy

Multiple rain shower head geometries (round, square, future) sharing a common reusable adapter and a common cartridge architecture is the correct platform direction for a modular system at this price tier. Our working assumption going into Phase 1 is that the adapter and cartridge are shared across the family and the shower head geometries are variant-specific, with the variant tooling strategy phased rather than launched in parallel. Phase 1 will confirm which sub-assemblies are truly shared, where variant-specific tooling is required, and the recommended geometry to tool first based on commercial priority and tooling economics.

03 — Volume & Timeline Targets

Programme Targets

The following reflects current working assumptions drawn from the provided brief, intake form, and discovery call notes. The pilot and first production run figures will be reconciled and validated through Phase 1.

Engineering Prototype Quantity. Approximately 100 units across sub-assemblies for design validation

Pilot / Marketing Launch Run. Approximately 1,000 units (to be confirmed in the Development Roadmap)

First Mass Production Run. Approximately 5,000 units (to be validated against pilot performance)

Year 1 Volume Forecast. Up to 1,000,000 units (to be confirmed in the Development Roadmap)

Target Unit Cost. To be validated through the Phase 1 Indicative Quotation

Target Timeline to First Pilot Units. Approximately 5 to 7 months from Phase 1 completion (indicative)

Target Markets. United States primary; premium positioning, California and hard-water markets

Funding Status. Funded

04 — Phase 1 Deliverables

Six Phase 1 Deliverables

Phase 1, Engineering Validation is the first paid engagement in the HelixFlo development programme. The work is engineering-led: an independent audit of the existing CAD and BOM, a focused engineering workstream on the cartridge manufacturability and sub-assembly architecture, a DFM, DFA, and DFX engineering assessment across all three sub-assemblies, supplier engineering engagement with indicative pricing, and a Development Roadmap that consolidates the output into a costed phase-by-phase pathway to qualified mass production manufacture.

Duration: approximately 4 to 6 working weeks from confirmation.

Phase 1 consists of the following six deliverables.

Engineering Kickoff Workshop

A working technical session with the Shield Works R&D team, not an introductory call. We walk through the HelixFlo product architecture, the existing CAD and BOM, Wynn's commercial and channel goals, and the three-sub-assembly strategy, and agree the engineering priorities and workstreams before work begins.

Independent CAD and BOM Engineering Audit

Written, annotated audit of the provided STEP models and BOM, with specific engineering findings and redline direction on priority areas. Focus is on the cartridge housing and helical geometry, the adapter material and process choice, and the shower head architecture. Output: annotated engineering commentary and a ranked list of recommended design revisions.

Cartridge Manufacturability and Sub-Assembly Architecture Workstream

Dedicated engineering workstream on the central technical question. Includes mouldability assessment of the internal helical geometry (parting line strategy, draft, undercuts, side action, ejection), water-tight sealing interface engineering between cartridge and adapter, material selection trade-offs across the three sub-assemblies, finishing strategy direction, and the sub-assembly architecture decisions that determine tooling investment and per-unit cost. Output: documented engineering position with trade-off analysis and recommended manufacturing direction for Phase 2 confirmation.

Preliminary DFM, DFA, and DFX Engineering Assessment

Written assessment covering DFM and DFA across the adapter, cartridge, and shower head sub-assemblies, tooling strategy and indicative tooling investment direction, finishing path selection, packaging scope direction, assembly sequence, and a structured risk register with mitigations. Preliminary at this stage against analysis and supplier data; full DFM execution, drawing release, and supplier qualification testing sit in Phase 2.

Supplier Engineering Shortlist and Indicative Quotation

Qualified supplier shortlist drawn from our Shield Works supply chain and wider network, with first-round engineering engagement to confirm capability and capacity on CNC machining and die-casting for the adapter, injection moulding for the cartridge, copper and copper-nickel fabrication for the shower head, and the cosmetic finishing processes appropriate to each sub-assembly. Engagement with Wynn's named KDF and activated carbon media sources to confirm supply qualification. Indicative unit pricing for the three sub-assemblies and the full system at multiple volume tiers, benchmarked against the shortlisted suppliers. Accuracy is subject to the defined level of readiness for manufacture; final unit costs are locked against specific supplier quotes as the Phase 2 development phases progress.

Development Roadmap (Full RTMP)

The 25 to 35 page consolidating document that carries the Phase 1 engineering output forward into Phase 2 and through to qualified mass production manufacture. This is the full Route to Market Plan for HelixFlo.

Development Roadmap (Deliverable 6) — Contents

Phase timelines and phase management costs across the full development programme.
Shield Works resource allocations and core deliverables across sampling, development, design optimisation (full DFM, DFA, DFX), prototyping, pilot run manufacture, mass production, and scaled production.
Consolidated written output of the Phase 1 engineering work, including the CAD and BOM audit findings, the cartridge manufacturability workstream output, and the DFX assessment.
Component-level bill of materials with material specifications and qualified supplier direction.
Mechanical engineering and DFM plan for the three sub-assemblies, including shared-platform and variant-specific tooling strategy for the shower head geometries.
Cosmetic finishing plan across the three sub-assemblies with indicative cost direction.
Filter media supply plan with qualified sources and incoming QC criteria.
Prototyping and iteration plan with validation gates.
Tooling strategy, variant phasing decisions, and indicative tooling investment budget.
Pilot run manufacture plan with QC gating criteria.
Mass production pathway and scaled production goals.
Packaging direction and indicative packaging cost.
Risk register with mitigations and owner assignments.

Note: Phase 1 is the first phase of the HelixFlo development programme. Phase 2 and subsequent development, tooling, certification, and production work is scoped and costed within the Development Roadmap for Wynn's approval before any execution begins.

Phase 1 Fee: $7,500 USD — payable in full on project confirmation.

05 — Indicative Development Envelope

Preview of the Phase 1 to Pilot Production Envelope

The figures below are preliminary ranges produced from our initial review and our experience with multi-component premium consumer products manufactured in China. They are shared ahead of the Phase 1 Indicative Quotation so that the shape of the investment is clear from the outset. They will be firmed up, detailed, and locked against specific supplier quotes in the Phase 1 output.

5.1 — Development pathway, Phase 1 to pilot production

Stage	Scope	Timeline	Indicative fee
Engineering refinement and DFM	CAD and BOM audit, DFM across three sub-assemblies, supplier drawings, finishing strategy	4 to 6 weeks	$8,000 – $14,000
Prototype build	First functional prototypes in target materials across adapter, cartridge, and one shower head geometry	4 to 6 weeks	$6,000 – $12,000
Prototype iteration (likely)	Second iteration on cartridge seal, finish quality, and any DFM-driven design changes	3 to 4 weeks	$4,000 – $7,000
Cartridge tooling	Injection mould for the cartridge housing including internal helical geometry	8 to 12 weeks	$15,000 – $30,000
Shower head tooling (per geometry)	Tooling per shower head geometry where injection-moulded components are used; metal fabrication tooling where applicable	8 to 12 weeks	$8,000 – $18,000 each
Pilot run	Pilot production for final QC validation and marketing samples	3 to 4 weeks	$4,000 – $7,000
Development total (before mass production)	Indicative envelope across the three sub-assemblies, one shower head geometry tooled, single prototype iteration	approx. 5 to 7 months	$45,000 – $88,000

Ranges assume the three sub-assemblies tooled with one shower head geometry as the first variant, a single prototype iteration, and finishing delivered through our qualified supply chain as part of the all-in unit cost. Additional shower head geometries are staged sequentially and quoted against tooling at the time the variant is committed. The envelope above excludes filter media procurement, sample shipping, and any third-party testing or certification fees, which are addressed separately in Section 6.

5.2 — Preliminary risk register

The risks below will be carried into the Development Roadmap with quantified mitigations. Surfacing them now signals where our engineering focus will be during Phase 1.

Risk	Likelihood	Impact	Primary mitigation
Helical internal geometry on the cartridge raises moulding complexity, undercut, or ejection issues	Medium	High	Mouldability assessment in Phase 1; parting line, draft, and side action options analysed before tooling commitment
Cartridge sealing fails to meet residential shower pressure reliability	Medium	High	Sealing interface engineering as part of DFM; sealing geometry and elastomer selection validated at prototype stage in Phase 2
Premium cosmetic finish on machined or cast metal parts inconsistent across batches	Medium	Medium	Finishing path locked in Phase 1; QC criteria integrated into incoming and outgoing inspection through our qualified supply chain
Multi-geometry shower head strategy drives tooling investment beyond the funded development envelope	Medium	Medium	Variant phasing strategy in Phase 1: which geometry to tool first, which to stage, what is genuinely shared across variants
Filter media supply variability (KDF, activated carbon) affecting product performance consistency	Low-medium	Medium	Qualification of named suppliers in Phase 1; supply agreement structure and incoming QC criteria defined in the Development Roadmap

Indicative unit pricing is not included at this stage. Material, process, and finishing decisions across the three sub-assemblies materially affect per-unit cost and will not be locked until the Phase 1 work is complete. Unit pricing at multiple volume tiers will be delivered in the Phase 1 Supplier Engineering Shortlist and Indicative Quotation.

06 — Exclusions

What Sits Outside Phase 1

The Phase 1 fee covers all six deliverables in Section 4, including engineering work, CAD and BOM audit, the cartridge manufacturability workstream, DFX assessment, supplier engagement, indicative quotation, and the Development Roadmap. The following are excluded and would be scoped and costed within the Development Roadmap itself or addressed through specialist external partners coordinated by Shield Works.

–

Industrial design refinement or any 3D CAD development work beyond the audit.

–

Full DFM execution, engineering drawing release, and supplier qualification testing.

–

Computational fluid dynamics (CFD) modelling, flow physics simulation, or any analytical or empirical validation of the internal helical flow performance. Flow geometry performance is the client's design intent and is not validated by Shield Works in Phase 1.

–

Filter media efficacy testing, residence time characterisation, breakthrough curve analysis, and any performance validation of the KDF or activated carbon media. These are specialist filtration testing workstreams and would be routed through external testing laboratories on Wynn's behalf if required.

–

Water treatment regulatory certification testing (for example NSF/ANSI 42, 53, 177, or equivalent), accredited test lab submissions, and associated fees. Certification pathway guidance is included in the Development Roadmap; execution is routed through external testing partners and quoted separately.

–

Prototyping, sampling, and physical testing.

–

Tooling and mould costs.

–

Filter media procurement and supply.

–

Shipping costs for physical samples or prototypes between China and the US.

–

Patent or utility model filing fees (guidance is included; filing costs are separate).

–

Production unit costs.

Note on the post-Phase 1 model

Once a supplier set is confirmed and production begins, C2W and Shield Works operate as Nguyen Mechanical Systems' manufacturing partner. Wynn receives a single unit cost for each HelixFlo sub-assembly and the full system that covers goods, assembly, quality control, supplier management, packaging, and logistics coordination. These are not billed as separate service fees. The Phase 1 Supplier Engineering Shortlist and Indicative Quotation is specifically designed to establish those unit costs with confidence before any production commitment is made.

07 — Investment & Payment Terms

Phase 1 Fee & Forward Commercials

Phase 1 Duration

4–6 Weeks

Approximately, from confirmation

Phase 1 Fee

$7,500

USD — Paid in full on confirmation

Phase 1 Fee — Engineering Validation

$7,500

USD — payable in full on project confirmation

Phase 1 work begins on receipt of cleared funds

All six Phase 1 deliverables in Section 4

Dedicated PM in our China HQ

Shield Works R&D, engineering and supplier teams

NDA in place; NNN extended to all engaged suppliers

Status: provisional, subject to the Engineering Review Call. Scope and fee are firm. Forward commercial model post-Phase 1: once a supplier set is confirmed and production begins, Wynn receives a single unit cost for each HelixFlo sub-assembly and the full system, inclusive of goods, assembly, QC, supplier management, packaging and logistics coordination. No separate service fees on top of unit cost.

08 — Safeguards & Clarifications

How We Keep Phase 1 Honest

Provisional status and engineering review

This proposal is provisional pending a dedicated Engineering Review Call between Shield Works R&D and the Nguyen Mechanical Systems team. The scope and fee are firm. The purpose of the call is to align Phase 1 emphasis against Wynn's real technical priorities, principally the cartridge manufacturability and the sub-assembly architecture across the three components, so that the Phase 1 output is built on the right starting assumptions.

Scope changes

If requirements change materially during Phase 1 (for example, a change in the number of shower head geometries tooled in the first phase, a material change in target volumes, or an addition of regulatory testing requirements), we will adjust cost and timeline accordingly and agree any changes before proceeding.

Quotation accuracy

The Indicative Quotation delivered as part of Phase 1 is subject to the level of readiness for manufacture. The cost envelope in Section 5 is directional. Final pricing is locked against specific supplier quotes inside the Phase 1 output and progressively refined through Phase 2 development.

Filter performance and water treatment certification

Phase 1 covers the manufacturability, sub-assembly architecture, and supply chain qualification of the HelixFlo platform. It does not include validation of the filter's flow performance, media efficacy, or water treatment claims. Where Wynn requires performance validation or third-party certification (NSF/ANSI or equivalent), Shield Works will identify and coordinate specialist testing partners as part of the Development Roadmap, with testing fees quoted separately and paid by Wynn to the testing partner directly.

CAD and BOM audit

Our review of the provided STEP files and BOM will be independent and written. Where the design is sound, we will confirm it. Where revisions are required, we will recommend specific changes and explain the reasoning. The objective is to give Wynn a defensible technical position from which to make the best commercial decision.

Intellectual property

Nguyen Mechanical Systems retains all intellectual property in the HelixFlo product, including design, BOM, and any derivative work produced under our engagement. Shield Works operates within an IP-secure, ISO-certified facility and operates under the NDA already in place between our teams. An NNN agreement covering all third-party suppliers engaged on the project will be put in place before any external engagement begins.

Timelines

The 4 to 6 working week Phase 1 estimate assumes reasonable availability for the Engineering Kickoff Workshop and follow-up technical discussions during the engagement. The 5 to 7 month Phase-1-to-pilot-production projection in Section 3 is indicative and assumes a single prototype iteration and one shower head geometry tooled as the first variant.

09 — Why C2W & Shield Works

A Single Accountable Engineering & Manufacturing Partner

Phase 1 is delivered by the same group of companies that takes the product through to qualified mass production:

Full-time dedicated project manager in our China HQ coordinating all suppliers, engineering resources, and the Nguyen Mechanical Systems team, with full visibility on who is making what and where.

In-house R&D, mechanical engineering, DFM and DFX, quality control, and audit resources, led by a mechanical engineer CEO (28 years including 8 years at Airbus) and a Head of R&D with over 12 years of China-based product engineering experience.

Over 20 years of proven track record delivering complex multi-component consumer products from China, with direct experience across CNC machining, die-casting, injection moulding, copper and stainless fabrication, and premium cosmetic finishing.

IP-secure, ISO-certified manufacturing facility (Shield Works, Zhuhai) available for sub-assembly integration, quality control, packaging, and warehousing.

Established supply chain across CNC machining, die-casting, injection moulding, metal fabrication, and premium cosmetic finishing, with Wynn dealing with a single commercial counterparty for the all-in supply.

Transparent factory selection and direct supplier relationships. No hidden middlemen, no opaque quotes, no surprises on quality.

End-to-end capability from concept through to qualified mass production, with packaging and 3PL services available through the same group of companies.

10 — Next Steps

From Engineering Review Call to Phase 1 Delivery

Wynn shares the HelixFlo CAD (STEP), 2D drawings with tolerances, and BOM with the Shield Works R&D team in advance of the Engineering Review Call so that the call is built on the same files.

Wynn confirms the proposed Engineering Review Call between Shield Works R&D and the Nguyen Mechanical Systems team (no cost, approximately 45 to 60 minutes). Focus: cartridge manufacturability and helical geometry, adapter material and process choice, shower head variant strategy, and cosmetic finishing direction.

On alignment from that call, Wynn confirms acceptance of this proposal and the Phase 1 fee.

C2W issues invoice for $7,500 USD.

On receipt of payment, we schedule the Engineering Kickoff Workshop with the Shield Works R&D team.

Phase 1 output, including the Development Roadmap, delivered within approximately 4 to 6 working weeks of the Engineering Kickoff Workshop, including the full development programme roadmap with costs and timelines for Wynn's approval.

This proposal is non-binding at this stage and is intended to give Wynn clarity on cost, structure, and what Phase 1 will actually produce. If you are happy with the direction, we can move to the Engineering Review Call at your convenience and proceed from there.

Best regards,

Mark Jacobs

CEO, C2W Group / Shield Works

May 2026