Usage Tips:Description [WIRELESS MAGNETIC SENSOR ALARM]: Alarm triggered after opening the front door or window. The alarm system will be activated when the door opens more than 0.6 inches. [SUPER LOUD ALARM]: 130dB Alarm siren not only can cause huge shock to thieves, but also wake you up while sleeping to avoid horrible accident. [EASY TO USE AND INSTALL]: Wireless remote control, easy to use. Two installation methods, stick with double-sided sticker or tie it with strap, no tools required. It is suitable for houses, apartments, mobile homes, offices, hotel rooms, garages and other entrance warning systems. [KEEP YOUR CHILDREN SAFE]: This magnetic wireless sensor door and window alarm is powerful enough to detect entry, let you know when your children open doors or windows to prevent children and babies from going out , whether you are inside or outside the house. Especially, if you have a swimming pool at home, it is very necessary to install a door alarm. [DO NOT WORRY NOT WORKING]: Anti-theft alarm can be used for one year without changing the battery frequently. Door magnetic battery: No. 7 battery (1.5V) * 2 units,Remote control battery: CR2032 battery (3V) * 1 piece. package:1sets ( not including batteries)