Description
The SM323-MT-AB pairs the SM323 Matter dimmer module with a knurled brushed antique brass metal faceplate. It is built on the same proven hardware platform as our Zigbee SM323 – same dimming circuitry, wiring and module size – but communicates via Matter over Thread instead of Zigbee, bringing native support across Apple Home, Google Home, Amazon Alexa and Samsung SmartThings.
Designed for the UK two-wire wiring standard, the SM323 Matter dimmer offers an ideal balance of compatibility, responsiveness, and energy-efficient performance for modern LED lighting.
⚙️ Key features
Matter over Thread technology
Ultra-fast, low-latency control on a self-healing Thread mesh network. Thread keeps the dimmer responsive even if your Wi-Fi is down, and the mesh grows stronger as you add more Matter-over-Thread devices.
Smooth, silent trailing-edge dimming
Reverse-phase (trailing-edge) control delivers precise dimming from 0–100% with no buzzing – the right technology for modern dimmable LEDs.
Multi-admin across every major ecosystem
Native support for Apple HomeKit, Google Home, Amazon Alexa and Samsung SmartThings – all simultaneously, via Matter. Pair once, control from every app. No proprietary apps, no vendor lock-in, no bridges.
UK two-wire compatible
Fits standard UK no-neutral switch positions without rewiring. A neutral connection is also supported if your back box has one – useful for higher loads or longer cable runs.
Secure, local control
Matter commands run locally over Thread – not through the cloud – for faster response, better reliability and improved privacy.
🔧 Technical specifications
- Part number: SM323-MT-AB (1, 2, 3 & 4-gang configurations)
- Protocol: Matter over Thread (Thread Border Router required – see below)
- Dimmer type: Trailing edge (reverse phase)
- Input voltage: 230 VAC, 50/60 Hz
- Max LED load: 150 W
- Max incandescent / halogen load: 350 W
- Module dimensions: 51 × 26 × 24 mm (same module as the SM323 V2 Zigbee – fits standard UK 35 mm-deep back boxes)
- Weight: 30 g
- Wiring: Live only, or Live + Neutral if available. Screw terminals accept 1.0–1.5 mm² solid or stranded cable
- Switch type: 2-way (retractive switch only)
- Faceplate finish: Brushed Antique Brass knurled metal
- Knob finishes: Multiple options to match the plate
📡 Thread Border Router required
Matter over Thread devices need a Thread Border Router on your network to communicate with your smart home ecosystem. Most modern hubs and smart speakers include one – chances are you already have one.
| Ecosystem | Matter-over-Thread | Supported Thread Border Routers / Hubs |
|---|---|---|
| Apple (HomeKit) | ✅ Yes | HomePod mini, HomePod (2nd gen), Apple TV 4K (2021+) |
| Google (Nest / Home) | ✅ Yes | Nest Hub (2nd gen), Nest Hub Max, Google TV 4K, Nest Wifi Pro |
| Amazon (Alexa / eero) | ✅ Yes | Echo (4th gen), Echo Show 8 & 10 (3rd gen), Echo Show 15 (2nd), Echo Hub, eero Wi-Fi routers |
| Samsung (SmartThings) | ✅ Yes | SmartThings Hub v3, SmartThings Station, Aeotec Smart Home Hub |
| Hubitat | ✅ Yes | Hubitat Elevation |
| Home Assistant | ⚠️ Partial | Matter Server add-on; basic on/off and dimming work today, advanced features still evolving |
🔧 Ideal for
- LED downlights and dimmable ceiling fixtures
- Retrofitting existing wall switches
- Reliable automation without Wi-Fi dependency
- Multi-ecosystem households mixing Apple, Google, Amazon and Samsung
Whether you are building your smart home from scratch or upgrading an existing setup, the SM323-MT is the intelligent choice for future-ready UK lighting control – the same SM323 hardware you can trust, now on the new universal standard.
Prefer Zigbee instead? See the SM323 V2 Zigbee Dimmer – same hardware, Zigbee 3.0 instead of Matter over Thread.
Reviews
There are no reviews yet