... low power standby consumption,no wiring required. GTS-112 DOOR&WINDOW ENTRY ALARM:safety guard brings safety to your home ... them separately to the both sides of the door or window,and there is magnetic sensor on the right ... position"on" when someone moves or opens the door or window,the guard will send out continuous sound to ... 6cmPackage:48pcs/ctn,Measurement:0.027CBM (GTS-112) DOOR&WINDOW ENTRY ALARM