

Overview
The SONOFF SNZB-02DR2, marketed as the AirGuard TH, is a room climate gauge with a 3.6 inch screen that is easy to read from a distance. It displays current temperature and humidity, the high and low for the day, the battery charge, and a comfort icon that appears when conditions move beyond the limits you choose.
It is well suited to nurseries, cellars, server cupboards, greenhouses and wine storage. With a Zigbee hub, readings are sent to the eWeLink app along with graphs and alerts, so you can keep an eye on a room without going into it.
- At a glance
- Brand
- SONOFF
- Model
- SNZB-02DR2
- Connects with
- Zigbee
- Model
- SNZB-02DR2
- Display resolution
- 0.1 °C and 1% RH
- Power
- 2 × AAA (LR03) batteries
What it does
Clear screen showing live readings, the daily peak and trough, and battery charge
Accuracy of ±0.2 °C across −20 °C to 60 °C, and ±2% relative humidity
Bluetooth proximity mode for quick checks, or Zigbee mode for remote readings and automations
History stored for roughly six months, with highest, lowest and mean curves, dew point and VPD
Threshold notifications, plus linked switches that can run a fan, dehumidifier or heater
Adjustable reporting thresholds to save battery, and a calibration offset for temperature and humidity
Specifications
From the manufacturer's data. Check the label on the device if your installation depends on a rating.
| Model | SNZB-02DR2 |
|---|---|
| Display resolution | 0.1 °C and 1% RH |
| Power | 2 × AAA (LR03) batteries |
| Size | 95 × 70 × 18.2 mm, about 99.3 g with batteries |
| Operating range | indoors, −20 °C to 60 °C, 5–95% RH, non-condensing |
Before you install
- Zigbee mode needs a hub; Bluetooth mode works without a gateway.
- There is no Wi-Fi radio, so the sensor cannot join your router by itself.
- Alexa and Google Home routines reach the sensor only through a supported hub.


