Loud Alerts: Door and window sensors are loud enough to detect entry, prevent kids and babies from getting out of the house, and protect your home office, garage, dorm, or apartment whether you're there or not. You're sure to hear its alerts from another room. Don't worry about young kids making a mess, just put it up high so they can't reach it. It can be used on sliding doors, windows, drawers, and refrigerators. | Smart Design: The alarm and magnetic strip are separated by more than 0.39 inches (10 mm) and it keeps going off until you close the door (make them connect) or turn it off (switch to button "OFF"). | Easy installation: wipe the flat surface, peel off the sticker, install the alarm on the door and the magnetic strip on the door frame. Done.Magnetic sensor switch detects your door or window. Easy to install and operate, press the on/off switch to turn power on/off, then insert 2 AAA batteries (batteries not included in the box), peel off the double-sided tape on the backpack, and attach the door handle alarm to your target location. | Power Saving: The battery used to power the alarm will last for more than a year [Note: 1. Remove the plastic insulating sheet inside the battery compartment before use. 2. Your door frame and window or door must be flush so that both components must be installed very flush. | Prevent Any Accidents - keep kids out of cabinets, above ground pools, alcohol. Monitor wandering, sleepwalking, elderly getting out of bed by themselves to avoid all kinds of dangers.