[3 Level of Sensitivities]: Hige-Midium- Low Sensitivities. Which depends on the distance door touch the door stop alarm.
[Powered by 9V Battery]: Powered by 9V battery, One piece can be used for a year under normal circumstances. (Note: Battery not include)
[User-Friendly]: No installation needed; just position the alarm behind any door (residential, lodging, etc.).
[Loud Alarm]: Very loud shrill that would definitely scare someone away with 120db alarm. Weight: 4.5 oz.
[Dual Function]: Can be used as a door stop alarm and door stopper, Its high damping rubber bearing can prevent the door sliding and prevent the bad guys into.