Hidden River Lab
6.5" x 4.75" NuTone / M&S Intercom Retrofit Adapter for eufy Video Doorbell E340
6.5" x 4.75" NuTone / M&S Intercom Retrofit Adapter for eufy Video Doorbell E340
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Overview
Replace a large legacy intercom door station with a modern eufy video doorbell while covering the original wall opening. This 6.5" × 4.75" two-piece intercom retrofit adapter by Hidden River Lab is designed exclusively for the eufy Video Doorbell E340 (Dual Camera), Model T8214.
Designed for many NuTone / M&S (Music & Sound) legacy intercom installations and similar-size openings, the adapter helps conceal the oversized wall cutout left after removing an older intercom door station. It creates a purpose-built mounting surface for the eufy E340 dual-camera video doorbell.
The two-piece interlocking design consists of a base plate and face plate. The face plate snaps onto the base plate with a positive click and is additionally secured with machine screws. The concealed fastening system provides a clean, finished appearance.
This adapter provides a 0° straight viewing angle without built-in horizontal or vertical angle correction. It is designed specifically for the physical mounting requirements of the eufy Video Doorbell E340, which features a dual-camera system for viewing visitors and the area near the doorstep.
This is a model-specific retrofit adapter, not a universal mounting plate. It is not interchangeable with adapters designed for other eufy doorbells, Ring doorbells, or other manufacturers.
Compatibility
✔︎ Designed exclusively for:
▪︎ eufy Video Doorbell E340 (Dual Camera) — Model T8214.
✔︎ Retrofit application: Many older NuTone / M&S intercom door stations and similar-size legacy intercom openings.
✔︎ Adapter size: Approximately 6.5" × 4.75".
✔︎ Viewing angle: 0° straight view without built-in horizontal or vertical angle correction.
✔︎ Mounting surface: Flat, stable surfaces.
✔︎ Application: Replacing a legacy intercom door station with the specified eufy E340 while covering the original mounting opening.
✖︎ Not compatible with:
✖︎ Other eufy Video Doorbell models, including previous-generation and newer models not explicitly listed as compatible.
✖︎ eufy Video Doorbell S330, S220, C210, and other eufy doorbell models.
✖︎ All Ring doorbell models, including Ring Wired Doorbell, Wired Plus, Wired Pro, Battery Doorbell, and their respective generations.
✖︎ Doorbells from other manufacturers, including Google Nest, Arlo, Wyze, Blink, Amcrest, and other brands.
✖︎ Non-flat mounting surfaces requiring specially shaped siding, brickmold, or other profile-specific adapters.
✖︎ Third-party mounting accessories or angle adapters unless specifically confirmed as compatible.
Important: This adapter is designed exclusively for eufy Video Doorbell E340, Model T8214. Please verify your exact doorbell model before ordering. Visually similar eufy doorbells may have different mounting dimensions and hardware requirements.
Electrical compatibility: This is a mechanical mounting adapter only. The eufy E340 can operate using its rechargeable battery or compatible existing doorbell wiring, according to eufy's specifications. This adapter does not convert legacy intercom wiring, provide electrical power, or guarantee compatibility with an existing intercom power supply.
What's Included
▪︎ 1 × 6.5" × 4.75" base plate — designed to cover the original legacy intercom opening.
▪︎ 1 × Doorbell face plate with an interlocking snap-fit attachment mechanism, designed specifically for eufy Video Doorbell E340.
▪︎ Machine screws to secure the face plate to the base plate.
▪︎ Self-tapping screws for fastening the appropriate doorbell mounting components to the adapter.
✖︎ Not included: eufy doorbell, original eufy mounting bracket, legacy intercom components, wall-mounting screws, wall anchors, electrical transformer, and wiring accessories.
Fit & Measurements
▪︎ Overall adapter size: Approximately 6.5" × 4.75".
▪︎ Construction: Two-piece design — base plate and interlocking face plate.
▪︎ Doorbell compatibility: eufy Video Doorbell E340 (Dual Camera), Model T8214 only.
▪︎ Viewing angle: 0° straight view.
▪︎ Mounting application: Legacy NuTone / M&S intercom retrofit installations on flat surfaces.
▪︎ Opening coverage: Intended to cover many existing 6.5" × 4.75" legacy intercom mounting areas and similar-size openings.
▪︎ Existing mounting points: May be reused where appropriate, depending on the original intercom installation.
Understanding the dimensions:
The 6.5" × 4.75" measurement refers to the overall adapter plate size intended to cover the original intercom mounting area. It does not guarantee that every opening with similar nominal dimensions will be completely covered.
Legacy intercom systems may have different wall cutouts, screw positions, recessed housings, and mounting arrangements. Please compare the existing opening with the adapter dimensions before ordering.
Doorbell-specific mounting:
The face plate is designed for the physical mounting requirements of the eufy Video Doorbell E340. The adapter creates a dedicated mounting interface rather than requiring the original intercom opening to match the much smaller doorbell footprint.
The adapter provides straight camera positioning without adding a horizontal side angle or vertical inclination. The final camera coverage depends on the doorbell's field of view, mounting height, and installation location.
→ Intercom systems and wall openings vary. Measure your existing opening and check the surrounding mounting surface to confirm that the adapter will provide sufficient coverage.
→ If you are unsure about fitment, send us a front-facing photo of the opening and its measurements before ordering.
Why Choose This Adapter
▪︎ Legacy intercom retrofit: Replace an outdated NuTone, M&S, or similar intercom door station with a modern eufy Video Doorbell E340.
▪︎ Opening coverage: Helps conceal the oversized wall cutout left after removing a legacy intercom station.
▪︎ Clean finished appearance: Provides a purpose-built mounting surface instead of leaving an exposed or mismatched wall opening.
▪︎ Model-specific mounting interface: Designed exclusively for the physical mounting requirements of eufy Video Doorbell E340 (T8214).
▪︎ Secure interlocking construction: The face plate locks onto the base plate with a positive snap-fit connection reinforced with machine screws.
▪︎ Concealed assembly hardware: The two-piece design helps keep fastening hardware hidden in the finished installation.
▪︎ 0° camera positioning: Provides a straight mounting orientation without additional horizontal or vertical inclination.
▪︎ Dual-camera installation: Creates a dedicated mounting surface for the eufy E340 dual-camera doorbell.
▪︎ Outdoor-ready construction: Manufactured from durable 3D-printed plastic intended for everyday outdoor mounting applications.
Materials & Finish
♺ Made from durable, outdoor-ready 3D-printed plastic.
▪︎ Designed and manufactured by Hidden River Lab.
▪︎ New condition.
▪︎ Intended for everyday outdoor mounting applications.
▪︎ Minor cosmetic artifacts may be visible due to the additive manufacturing process, especially on internal or non-visible surfaces.
▪︎ External surfaces are designed to provide a clean finished appearance once installed.
Installation Notes
Basic mounting tools may be required (e.g., screwdriver). Follow eufy's instructions for mounting the doorbell, battery installation, optional electrical connections, and final setup.
▪︎ Step 1 — Verify compatibility. Confirm that your doorbell is the eufy Video Doorbell E340 (Dual Camera), Model T8214. This adapter is not intended for other eufy or third-party doorbell models.
▪︎ Step 2 — Prepare the installation. Remove the old intercom door station and safely manage any remaining wiring. If electrical wiring is present, disconnect power before handling it. Do not assume that the old intercom wiring or power supply is compatible with the eufy E340.
▪︎ Step 3 — Install the base plate. Position the 6.5" × 4.75" base plate over the old intercom opening and secure it to the wall using appropriate mounting hardware for the installation surface. Reuse existing mounting locations where suitable.
▪︎ Step 4 — Attach the face plate. Align the face plate with the base plate and press firmly until the interlocking mechanism engages. You should feel and/or hear a distinct click when the face plate is fully seated.
▪︎ Step 5 — Secure the assembly. After the face plate clicks securely into the base plate, secure the assembly with the included machine screws.
▪︎ Step 6 — Verify engagement. Confirm that the face plate is fully seated, securely interlocked, and properly fastened before installing the doorbell.
▪︎ Step 7 — Prepare the eufy mounting components. Position the original eufy E340 mounting bracket or other required mounting components on the completed adapter assembly, following eufy's instructions. If using compatible existing doorbell wiring, plan the wiring route and ensure that wires will not be pinched.
▪︎ Step 8 — Secure the mounting components. Fasten the appropriate eufy mounting components to the adapter using the supplied adapter hardware as applicable. Confirm that the mounting components are properly aligned and securely attached.
▪︎ Step 9 — Mount the doorbell. Install the eufy Video Doorbell E340 onto its mounting assembly following eufy's installation instructions. Ensure that the doorbell is properly seated and its retaining mechanism is engaged.
▪︎ Step 10 — Verify installation. Confirm that the adapter is securely fastened, the doorbell is properly mounted, and both cameras have an unobstructed view of their intended areas.
▪︎ Step 11 — Complete setup. Follow eufy's instructions for battery installation or approved wired-power configuration, device setup, and final operation.
For best results, install on a flat, stable surface and weather-seal the installation as appropriate for your wall, opening, and outdoor environment.
Electrical safety: The adapter does not replace the electrical requirements of eufy Video Doorbell E340. Legacy intercom systems may use different wiring and power supplies. If existing wiring requires modification or compatibility is uncertain, consult a qualified electrician. Never connect an unverified intercom power supply directly to the doorbell.
Color & Image Note
Actual product color may vary slightly due to lighting, photography, and display calibration. Images may show eufy doorbells, original eufy mounting components, legacy intercom components, or example installations for illustration purposes. These components are not included unless explicitly stated.
Disclaimers & Policies
Brand & Affiliation Disclaimer
This is an aftermarket intercom retrofit adapter made by Hidden River Lab. Hidden River Lab is not affiliated with, sponsored by, or endorsed by eufy, Anker, NuTone, or M&S. eufy®, NuTone®, and M&S® are trademarks of their respective owners. Brand names are used solely to identify product compatibility and intended retrofit applications.
Liability Disclaimer
Installation and use of this product are the purchaser's responsibility. To the extent permitted by applicable law, Hidden River Lab is not liable for damage to devices, wiring, mounting surfaces, exterior finishes, or property; loss of functionality; or personal injury resulting from improper installation, misuse, unauthorized modification, inadequate sealing, or unsuitable environmental conditions. If unsure about installation, consult a qualified professional. Nothing in this notice limits rights or remedies that cannot legally be excluded.
Intellectual Property Notice
The product design, images, text, and related listing content are intellectual property of Hidden River Lab. Purchasing this item does not grant any license to copy, reproduce, manufacture, reverse-engineer, or commercially exploit the design in whole or in part.
Support
Not sure whether your old NuTone / M&S intercom opening matches this 6.5" × 4.75" retrofit adapter or whether you have the correct eufy doorbell model? Send us photos of your doorbell, its exact model number, and photos or measurements of the old intercom opening. We'll help verify compatibility and mounting coverage before ordering.
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