For hall and closet, all interior doors where a simple latch is all that is required. Both bell-shaped knobs always free; no locking mechanism. DOOR PREP: 2-1/8 in Cross Bore, 1 in Edge Bore, 1 in x 2-1/4 in Latch Face. BACKSET: 2-3/8 in standard and adjustable to2-3/8 in or 2-3/4 in optional. DOOR THICKNESS: 1-3/8 in to 1-3/4 in CYLINDER: 5-pin. FACEPLATE: 1 in x 2-1/4 in STRIKE: 2-1/4 in full lip. BOLT: 1/2 in throw. HANDING: Reversible for right or left hand doors. ANSI/BHMA: Grade 3.