Description:  - Induction door and window opening and closing: Determine the opening and closing of doors and windows by sensing the distance between the main body and the magnet.  - Remote push notification: Detecting the opening and closing of doors and windows, the app remotely automatically pushes reminders to keep the home safe at all times. (Need to set the linkage strategy in the Mijia app).  - Connect to Mijia Smart Linkage: With other Mijia smart products, set up linkage strategies to realize multiple smart scenarios.  - Bluetooth Low Energy 5.0: Use Bluetooth 5.0 low energy, battery life up to 8 months.  - Small body can be posted anywhere: Small size, high appearance, and rich application scenarios. Just stick and use, no tools required.  - Installation Notes: When installing, please align the main body and the center line or top of the magnet, and ensure that the distance between them is <15 mm.   General Parameters:  Size:  Main body: 44*21.5*13mm;  Magnet: 29*14*7mm;  Color: White;  Battery: CR1632 Button battery;  Weight:  Main body 6g(Without battery);  Magnet 7g;  Bluetooth Type: Bluetooth Low Energy 5.0;    Package Included:   1 * Door & Window sensor;  1 * Magnet;  1 * User Manual