Doberman Security Slim Window Alarm Work with Sliding Windows and Vibration Sensing 4 Pack Built-in sensitive vibration sensor Alarm triggered after window vibration by an intruder The perfect device to detect intruder break-in via the window of your house, apartment, store, office, R.V. or dorm room Loud 100 dB alarm / Warning sticker to deter theft Batteries : 2 x LR44/AG13 button cell batteries.(Included)