The GLASS BREAKAGE ALARM is a super cost effective vibration alarm that is specially designed to detect vibration in glass. Just attach the unit to any window or door glass and if the glass is disturbed in any way, the alarm will sound for 30 seconds and then rearm itself. This unit can also be used to protect other property such as computers, stereos, TVs, etc. Powered by one 12V battery (included) and utilizes a very strong adhesive double-sided tape.