just put the door stop alarm behind the door, when the door open, it will trigger door stop alarm sensor, and then it will make a 120db alarm voice to scare interloper. You can take it anywhere, and have a nice sleep at home, hotel etc
Product feature:
* stainless steel cover.
* high quality.
* wireless.
* adjustable high-medium-low sensitivity.
* vibration sensor.
* no installation required, easy for travelers to carry.
* wedge-shape design to fit any hinged door.
* 120 db high-pitched continuous siren when activated.
* can be used as a doorstop when power switch is turned off.
* powered by a 9-volt battery. (not included)
* mini size, space-saving.
* no installation required.
* special design for use at home, office, hotel rooms.
* ensures your safety and peace of mind at home or when travelling.
Application:
home, hotel, office...