U/B 4 Pack Door Window Alarm, Home Personal Security Wireless Sensor Burglar, Wireless Alarm for Kids Safety, Office,Home Security Protection

SMART DESIGN : The alarm and magnetic stripe are separated more than 0.39inch(10mm), it keeps going off until you close door(make them connection) or turn it off(switch to the button "OFF").
Battery for power supply can be used for more than one year(3 * LR44 batteries included per alarm )(NOTE: 1. Take out the plastic insulation sheet in battery compartment before use, 2. The small triangle on the side of the strip magnet is aligned with the small triangle on the side of the alarm with a spacing of less than 0.39inch(10mm), 3. Your frame and window or door must be flush, make these two components must be installed very flush with one another)
EASY INSTALLATION :Wipe the flat surface, peel off sticker, mount the alarm on door and magnetic stripe on door frame.
Big LOUD ALARM :door window sensors loud enough to detects entry, prevent kids and babies going out the house, protecting your home office, garage, dorm room, or apartment whether you are in or out. You can definitely hear it from another room to alert you. No worry the young children could mess with it, just have it up high where they can't reach it. Work on sliding doors, windows, drawer, fridge.
Size: 2.52" x 1.67" x 0.66, no much space needed to install. It has 4 adjustable settings (on/off). Package include 4 door alarm.