The N1178GSHK-ST from Nascom is a recessed 1" switch for steel/wood doors with shark magnet and wire leads, gray. The N1178 SHK Series is a 1" recessed stubby door contact couple with the patented SHARKTM magnet. The set is designed for residential, commercial and industrial steel and wood door applications. The N1178 SHK is the installer's choice of contact configuration because the contact set is designed to cut installation times. Just a pinch of the springs installs the SHARKTM magnet permanently and the powerful rare earth magnet helps to prevent false alarms caused by shifting or warping doors. The N1178 SHK Series is designed for installation in every type of hinged door including wood doors.