BIG LOUD ALARM: Door window sensors loud enough to detect entry, prevent kids and babies from going out of the house, protecting your home office, garage, dorm or apartment whether you are inside or outside. You can definitely hear it from another room to alert you. Don't worry about young children might play with it, just place it high where they can't reach it. Work on sliding doors, windows, drawers, refrigerator. Prevent kids and babies from going out of the house without notice. Protect your home from burglars in your home windows and doors. EASY INSTALLATION: Wipe the flat surface, peel off the sticker, mount the alarm on the door and the magnetic strip on the door frame. Done! Easily mounts by adhesive. Tap on the window or door. Ideal entry warning for homes, apartments, mobile homes, offices, hotel rooms, garages, etc. Note: The data is manual measurement, please allow 1-3cm error, due to differences between light and display, there will be a certain color difference, the specific received in kind shall prevail.