The Sonoff SNZB-04PR2 SenseGuard DW Gen2 is a Zigbee 3.0 smart sensor designed to monitor the status of your doors and windows. It consists of a polycarbonate transmitter and a detachable magnet, which can be mounted either horizontally or vertically depending on your installation needs. The system triggers an alert whenever the gap between these two components exceeds 30 mm horizontally or 15 mm vertically. Powered by two AAA batteries, this compact device is built for longevity with a battery life that can reach up to three years. To ensure your home remains secure, it includes anti-tamper detection that notifies you via your app or gateway if the sensor is interfered with. Weighing only 45.1 g and measuring 90 x 26 x 13.5 mm, it blends discreetly into most interiors. To function, the sensor requires a Zigbee gateway and integrates well into various ecosystems; you can connect it to Apple Home through a Matter Bridge like the eWeLink CUBE or use it with Home Assistant via a SONOFF Dongle. Each package comes ready for quick installation with 3M adhesive included.