Glass Break Alarm With 125dB Loud AlarmOur window alarm has 125dB loud alarm built-in vibration sensor, it can effectively detect vibration glass breakage sound an alarm. 125dB loud alarm can deter scare away the thief. Easy To Install Use Glass break detectors is very easy to install, it can be installed in less than a minute, no no wiring is required, just peel stick the alarm to the desired position to the window, then press the on\/off switch, LED flashing making a 'Di' sound, the alarm is activated ready to protect your home. Vibration Sensitivity Adjustment Design Window Alarm Glass Break Detectors has sensitivity adjustment function, you can adjust the vibration sensitivity according to your your needs, which can prevent false alarms, turn to the tip, the lower the sensitivity.turn to the flat end, the higher the sensitivity. Battery Operated Window AlarmWindow Vibration Sensor Alarm is powered by 3 batteries, battery life battery stby can be up to 1 year, so you don't need to replace the battery frequently, when the battery voltage is lower than 3V, the LED will flash remind you to replace the battery.