Home Security Sounds Powerful Alarm when your Door or window or cupboard is opened. The pack contains Main unit panel - with DY adhesive tape (5 cm X 2.75 cm X 3 cm) Three piece 1.5 VLR44 button cell Features No Wiring or installation required. Just Remove the sticker and stick on your door / window or cupboard. Magnetic sensor switch detects entry protecting your home or office whether you are in or out. 90 Db instant alarm upon entry,Operates by 3 pcs. 1.5V LR44 button cell,100% imported with Japanese components, Easy to install - takes less than 2 minutes, Zero maintenance - install and forget.