This is a door stop with a stainless steel pressure plate, a nonslip bottom, 3 sensitivity levels, low, medium, and high, and a 120dB siren, once someone opens the door, the door stopper alarm will go off the first place, they will scare away bad guys and helps wake you and give you time to find help. Easy to install and portable, small enough to carry in a pocket or handbag. Portable door locks provide effective safety and protection for hotels, apartments, dormitories, and bathrooms.