Overview: This is a door and window alarm sensor. The door alarms can work with alarm system. The door alarm sensor detects the opening status and immediately sends alarm notification message to the APP. Features: *With low battery remind function *Low-consumption chip design, which can make it work long time. *High Sensitivity. Excellent design, tiny and fashion. Easily install with stickers. *Simply attach one piece to your door or window, and attach the other piece to the door or window frame. *Ideal intrusion warning for homes, apartments, mobile homes, dorms, offices, hotel rooms, garages, etc. Specifications: Battery: LR44*3 Voltage: 4.5V Current: 60mA Volume: 120dB Action distance: 15mm Launch distance: 150m (open area) Quiescent current: 5A Emission current: 10mA Battery life: 12-18 months Operating environment: -10-50 (14-122) Package Information: Package Size: Approx. 11.5*6.5*4.5*cm Package Weight: Approx. 150g PackageList: 4* Wireless Door / Window Sensor 1 * English manual