For keyed exterior doors. Both bell-shaped knobs lock or unlock by key outside or turnbutton inside. 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 2-3/8 in and 2-3/4 in optional. DOOR THICKNESS: 1-3/8 in to 1-3/4 in . CYLINDER: 5-pin. FACEPLATES: 1 in x 2-1/4 in round corner. STRIKES: 2-1/4 in full lip round corner. BOLT: 1/2 in throw. HANDING: Reversible for right or left hand doors. ANSI/BHMA: Grade 3.