125dB Loud Alarm for Glass Break Detection: Our window alarm features a loud 125dB alarm and a built-in vibration sensor, effectively detecting vibrations and glass breaks to trigger an alert. The high-decibel alarm can deter and scare off intruders. Easy to Install and Use: These glass break detectors are incredibly simple to install, taking less than a minute with no wiring required. Just peel and stick the alarm to your desired window location, then press the on/off button. The LED light will flash and emit a 'Di' sound, indicating the alarm is activated and ready to protect your home. Adjustable Vibration Sensitivity: The window glass break detector alarm includes a sensitivity adjustment feature, allowing you to customize the vibration sensitivity to your needs and prevent false alarms. Turn towards the pointed end for lower sensitivity, and towards the flat end for higher sensitivity. Battery-Powered Window Alarm: Powered by 3 batteries (not included), this window alarm with a window vibration sensor offers a standby time of up to 1 year, reducing the need for frequent battery changes. When the battery voltage drops below 3V, the LED light will flash to remind you to replace the battery. Wide Application: This family security alarm is versatile and perfect for your home, office, garage, dorm room, or RV. Number of pieces delivered: 2 Color: White Size: 72mm in diameter