Arrow MK31 Communicating Knob Lock

Arrow MK31 Communicating Knob. Arrow MK Series offer the Security Professional simple solutions to accessibility requirements. Their clean designs, architectural finishes and available functions make them ideal for commercial applications where heavy duty grade one hardware may not be necessary. Arrow MK31 Communicating Knob: Dead locking latch bolt operated by knob from either side. Turning key in either knob locks or unlocks its own knob independently. Do not use on doors in rooms that have no other entrance.   Features Lock Chassis: Cold rolled steel with zinc dichromate finish for corrosion resistance. Requires standard 2-1/8" (53.97 mm) bore through door.Backset: 2-3/8" (60.32 mm) standard. 2-3/4" (69.85 mm), 3-3/4" (95.25 mm) and 5" (127 mm) available.Door Thickness: 1-3/8" (34.92 mm) to 1-3/4" (44.45 mm)Latch: Brass with 1/2" (12.7 mm) throw. Latch housing is steel, with zinc dichromate finish for corrosion resistance. 7/8" (22.225 mm) bore in edge of door is required.Latch