100% Brand New and High Quality Magnetic sensor switch detects entry Ideal guardian against the unwanted intruder whether you are in or out， keep yourself and your property safe and security Easily attach the main sensor on the door/window and attach the stick adjacent the main sensor on the door/window frame with the adhesive tape (included) Handy ON/OFF switch: in the state of "ON"， the sensor will emit the alarm signal as long as someone opens your door or window Super loud 90 dB alarm Powered by 3* LR44 button cell (included) Included1 x Alarm Unit 1 x Magnetic Sensor