Welcome to the store! 1. Warning Message: When the door and window are opened illegally, the door sensor sends real-time alarm signals, and users can receive alarm information remotely via mobile phones. 2. Real-time Recording: The mobile phone app records the status of the door and window for you, check the records anytime and anywhere, protect you and your family's safety all day long, and record every detail. 3. Intelligent Linkage: The door window sensor can be connected to other smart devices to form smart scenes, such as triggering "turn on the light" when the door or window is opened. 4. Function: The contact sensor can detect doors, windows, electrical appliances, and furniture cabinet doors, drawers, and other items that are opened or closed, more practical, making your home safer. 5. Easy Installation: Easy to install, no complicated operation and tools required, just use the sticker, convenient to use, firm and durable, has a long service time. Item Type: Door Window Sensor Material: ABS Color: White Communication Mode: WiFi 802.11 b/g/n Function: Detect doors, windows, electrical appliances, and furniture cabinet doors, drawers, and other items that are opened/closed Battery Type: 2xLR03 Battery (Not Included) 1 x Door Window Sensor 1 x Secondary Sensor 2 x Sticker 2 x Screw 2 x Nut Setter 1 x Reset Pin 1 x User Manual Your satisfaction is our top priority. We will provide you with the best service. If you encounter any problems after receiving the product, such as damage, incorrect quantity, etc., please contact us immediately and we will provide you with the best solution!