The Avidsen Mini-Alarm with magnetic contact (such as model 100324) is a small, battery-powered security device. It uses a loud 100 dB to 120 dB built-in siren that sounds instantly when a door or window opens and the magnetic parts separate. Loud Siren: Built-in alarm sound reaches 100 dB to 120 dB to scare away intruders.Easy Setup: Mounts quickly on doors or windows using double-sided adhesive tape with no wiring needed.Dual Function: Acts as an intrusion alarm or a simple entry chime depending on your setting.Compact Design: Small parts align side-by-side on the frame and moving panel.