This attractive glass break sensor monitors for the sound of breaking glass up to 30 feet away using patent-pending CAIR technology and 3-stage statistical analysis. False alarms are virtually eliminated. 1/4" thick. Can be used with plate, wired, tempered and laminated glass 1/8" to 1/4" thick. N/C contacts. 9-16VDC power required. Add flush-mount kit for in-wall installation. The Slimline Glass Break Detector can be directly screwed to the wall. However, if precise directional positioning is required, use an optional mounting bracket. The Glasstech Detector Flush Mount Kit contains (1) Slimline Glass Break Detector and (1) Flush Mount Kit.