Applicable to multiple scenarios -- Easily mounted by adhesive. Type to window or door. Ideal entry warning for homes,apartments,offices,hotel rooms,garages,and more！ | Easy to use -- Magnetic switch detects your door or window.Easy stick installation and operation, press on/off switch to power on/off then insert 2 PCS AAA battery (battery do not contain in the box),tear the double-sided adhesive on the backpack, paste the door knob alarm on your target position. | Super loud 90 dB alarm -- When someone opens the door or window illegally (the relative position of the primary and secondary parts changes), the alarm can issue a strong alarm, warning the intruder to leave and remind the owner. prevent kids and babies going out the house, protecting your home or office whether you are in or out. | High quality -- Super suitability and stability. 100% New and high quality | Package include -- 15 packs super loud, suitable, stable, dustproof window door alarms