No installation is required, you simply place the battery-powered doorstop at the base of any door, turn it on and go about your business. Plus it has a nonskid bottom so you don't have to worry about it moving around.
Features:
1. Press the button to "L", and start the alarm. Press the button to "H", and turn on the sensor function.
3. It is a good helper when you travel, on business, and live alone, providing effective security and protection for hotels, apartments, dormitories, bathrooms, and bedrooms.