Unlock the outside knob with a combination; the inside knob is always unlocked. These handles are mechanical and do not require electrical wiring or batteries. They are UL Listed for use with three-hour fire doors.

Select a knob with the correct backset distance (the distance from the door’s edge to the center of the knob's mounting hole) for your door. Latch bolt projection is the length the latch bolt extends from the door's edge.