The glass break detector has the capacity to detect glass breakages. It has a built-in transmitter to send an alarm signal, and has a built in back up battery.
Specification:
Dimension : Round = 3.4 in. diameter by 0.83 in. D (8.6 cm diameter by 2.1 cm D). Square = 3.4 in. H, 3.4 in. W, 0.83 in. D (8.6 cm H, 8.6 cm W, 2.1 cm D).