SwitchBot Door Alarm Contact Sensor- Smart Home Security Wireless Window Alarm and Door Sensor, Add SwitchBot Hub to Make it Compatible with Alexa (3)
 
Product Features
  

         
[Window & Door Alarm Sensor for Home Security] SwitchBot Contact Sensor can detect the opening/closing of doors and windows, guarding security of the elderly, children, and pets. With the built-in light sensor, it will automatically trigger the Switchbot Bot to turn on the light when someone moves when the environment goes dark. The magnets need to be aligned with the bottom of the body, and the distance between the two components needs to be less than 1.2 inches (30mm).