The N175W-STFB from Nascom is a recessed 3/8" stubby press fit open loop switch / magnet set, wire leads, white. The N175 Series is a stubby 3/8" recessed contact, protects all nonferrous (e.g. wood, aluminum and vinyl) doors and windows, in both residential and commercial applications. The N175 is the installer's choice of contact configuration where drill depth is a consideration and excellent air and side-to-side gaps are required to stop false alarms, caused by shifting or warping doors and windows.