Glass Break Detector senses the shock and the window is opened the alarm will the double type. Set of 2. [Features] · The breaking of the glass Detector senses the shock and the window is opened the alarm will the double type. · Shock sensing vibration instead of glass breaking and shocks, detection and as such, passerby, etc. by rain or wind, large vehicles, etc., and do not have to worry to be false positives. Detector for shock and the breaking of the glass to glass windows, you can continue ringing loud alarm (approx. 90dB/50 cm) is about 25 seconds. Body Thickness only 8 mm, Fits most windows and without hiccups on the opening and closing. · during the vigilance/Unlock the at a glance that large, easy to operate slide switch. The Round Textured Glass on Glass (surface) can be installed. * Any larger than the decorative glass has some fitting may not be available.