Features: Non-Skid Door Stopper: The door stopper alarm in "on" status when door pressure is applied the door alarm will be triggered while make extremely loud 120db alarm. Easy to Install: No wiring needed; battery-operated (requires 1x9V battery not included);place it under the door the gap bewteen the bottom of the door and the floor should be 10mm. Dual Function: This door stopper security alarm can be a door stop alarm or a door stopper when the alarm being triggered and the meantime it will keep the people outdoor from you it's safe. Wide Use: Add a portable door lock to provide effective safety and protection for Hotels Apartments Dormitories Bathrooms Bedrooms. Customer Service: With customer satisfaction as our first priority we offer a satisfaction service for all of our merchandise. If you have any problems please contact us in time. We will give you replies as soon as possible. Specification: Voltage: 4.5 (V) Operating Current: 60 (mA) Volume: 130 (dB) Package Size: 6*4*12cm Color: White Gray Notes:Please allow slight tolerances in size due to manual measurement and lighting in photography may result in a difference in color than in real. includes: 1* Security Alarm "