Features: 1.Alert Message: When door and window is opened illegally, door sensor will send alarm signals in real time, and users can receive alarm information remotely through mobile phones. 2.Real Time Record: Mobile phone APP records the status of the door and window for you, checks the records anytime and anywhere, guards the safety of you and your family all day, and records every detail. 3.Intelligent linkage: Door window sensor can be connected with other smart devices to form smart scenes, such as triggering the "turn on light" when the door or window is opened. 4.Function: Contact sensor can sense door, window, electrical appliances and furniture cabinet doors, drawers and other objects open or close, more practical, make home more safety. 5.Easy Installation: Eassy to install, no complicated operation and tool is required, just use sticker, convenient for using, firm and durable, have a long service time. specification:Item Type: Door Window Sensor Material: ABS Color: White Communication Mode: WiFi 802.11 b/g/n Function: Sense door, wndow, electrical appliances and furniture cabinet doors, drawers and other objects open/close Battery Type: 2xLR03 battery (not included) PackageList:1 x DoorWindowSensor 1 xSecondary Sensor 2 x Sticker 2 x Screw 2 xNut Setters 1 xReset Pin 1 x User Manual