
Sonoff SenseGuard DW Gen2 Zigbee Door & Window Sensor | SNZB-04PR2
The SONOFF SenseGuard DW Gen2 (SNZB-04PR2) is a slim Zigbee door and window contact sensor. It reports when a door or window opens or closes, sends a tamper alert if the sensor is forcibly removed, and can trigger smart scenes such as sounding a gateway alarm, starting camera recording or turning off heating when a window is left open.
It runs on two standard AAA batteries, with up to 3 years of battery life according to SONOFF.
Color: White

Open/Close Alerts and Smart Scenes: The sensor detects the distance between the transmitter and the magnet, so you get an app notification whenever the door or window changes state. That status can also start automations — for example arming a SONOFF gateway, switching on a siren or starting a camera recording.

Tamper Detection: If someone removes or damages the sensor, it sends an instant tamper alert to the app and can trigger a smart scene, so the sensor itself cannot be quietly taken off the frame.

Flexible Installation: The sensor supports both horizontal and vertical mounting, which helps on wide gaps, narrow frames or uneven doors and windows. The sensor weighs 45.1 g including batteries.
AAA Battery Power: Two standard AAA batteries power the sensor, which keeps replacements easy and inexpensive.

Who it's for / Works with: Home security and energy-saving automations on doors, windows, cabinets and gates. SONOFF lists these Zigbee hubs: SONOFF ZBBridge, ZBBridge-P, ZBBridge-U, NSPanel Pro and iHost (eWeLink app); Home Assistant via ZHA or Zigbee2MQTT with a SONOFF Dongle; FRITZ!Box 7690; Aeotec Smart Home Hub V3; and Amazon Echo (Plus 2nd Gen, Echo 4th Gen, Show 2nd Gen).
Good to know: A Zigbee hub is required. On the older ZBBridge, only open/close status and battery level are supported. Using it with ZHA currently needs a script from SONOFF's help center, and tamper status in SmartThings also needs a script; NSPanel Pro needs firmware v4.3.0 or later.
Technical Specifications
| Specification | SNZB-04PR2 |
|---|---|
| Product name | SenseGuard DW Gen2 (SenseGuard series) |
| Model | SNZB-04PR2 |
| MCU | TLSR8656F512ET32 |
| Wireless | Zigbee (IEEE 802.15.4) |
| Input | 3V ⎓ |
| Battery | 2 × AAA (LR03) |
| Battery life | Up to 3 years |
| Net weight | 45.1 g (with batteries) |
| Dimensions | Transmitter 90 × 26 × 13.5 mm; magnet 31 × 14 × 6.5 mm |
| Casing material | PC |
| Working temperature | -10°C to 60°C |
| Working humidity | 5–95% RH, non-condensing |
📄 User manual: Download the official SONOFF SNZB-04PR2 user manual (PDF)