Usage Tips: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. Prevent kids and babies going out the house without notice. Protect your house from thiefs break in your house's windows and doors. EASY INSTALLATION :Wipe the flat surface, peel off sticker, mount the alarm on door and magnetic stripe on door frame. Done! Easily mounted by adhesive. Type to window or door. Ideal entry warning for homes, apartments, mobile homes, offices, hotel rooms, garages, and more! Note: The data are manual measurement, please allow a 1-3cm error, due to the differences between the light and the display, there will be a certain color difference, the specific received in kind prevail.