Features 1、Real Time Sensing: The home automation sensor offers real time sensing of opening and closing status through distance sensing between the main body and magnet. Sends signal every time they come together and separate at a set distance. 2、APP Control: Receive notifications on your phone when you forget to close door or window or when they are opened while you are away. Check the opening closing records and ensure home security for Mijia App. 3、Versatile Application: Not just for door or window, the home security sensor can be used on drawers, cabinets, and any other openable or closable items. Stay informed of any abnormal openings and take action promptly. 4、Automatic Video Recording: The camera automatically takes snapshots if someone intrudes. When door and window are opened while away, the smart door sensor records a short video and sends it to your phone to protect your home. 5、Energy Saving: The door open sensor automatically closes purifiers when window opened for ventilation. Save energy and ensure peace of mind with automatic control of purifiers and AC when the window is opened. Specifications Item Type: Door Window Sensor Bluetooth: Low Power Bluetooth 5.0 Battery Type: CR1632 Battery 50mAh (Included) Weight: Approx. 30.00g / 1.06oz Package List 1 x Receiver 1 x Transmitter 1 x Instruction Manual