Aqara - T1 Door and Window Sensor- Requires Hub product, Supports Apple HomeKit, Alexa, Google, SmartThings - White

Aqara Door and Window Sensor T1 detects the open and close state of doors or windows through the distance between the sensor unit and the magnet. It consumes a minimal amount of energy. No tools are required, just stick it to the desired place and use it in a dozen of possible use cases.