Feature: 1. Detecting if a window or door is closed in real time via Aqara or Home APP. 2. Connecting with other smart gateway devices to control your home appliances easily. 3. A sensor subject and a magnet included to ensure accurate detection. 4. Power by button battery for long endurance. 5. Mini sized, simple operation, no need other tools. Specification: 1.Description : This door and window sensor installed on your door or window at home to always know if they are opened or closed, smart connection with other Aqara smart accessories via APP make your life easier and convenient. 2.Features : Detecting if a window or door is closed in real time via Aqara or Home APP. Connecting with other smart gateway devices to control your home appliances easily. A sensor subject and a magnet included to ensure accurate detection. Mini sized, simple operation, no need other tools. Power by button battery for long endurance. 3.Parameters: Item name: Aqara Door and Window Sensor E1 Model: MCCGQ14LM Battery: CR1632 Working temperature: -10 - 50℃ Working humidity: 0 - 95% RH Max. sensing distance: 22mm Size: 41*22*11 mm 4.Note: If you need to realize smart linkage with other smart devices, a Zigbee gateway is required. (the gateway needs to be purchased by yourself) There is a little of difference according to manual measurement. 5.Package List: 1 * Door and Window Sensor E1 Package List: 1 * Door and Window Sensor E1