Description For keyed exterior doors. Rounded design to proportionally fit the palm of the hand. Both knobs lock or unlock by key outside or turnbutton inside. DOOR PREP: 2-1/8" Cross Bore, 1" Edge Bore, 1" x 2-1/4" Latch Face. BACKSET: 2-3/8" standard and adjustable 2-3/8" and 2-3/4" optional. DOOR THICKNESS: 1-3/8" to 1-3/4"; 2-1/4" doors optional. CYLINDER: 5-pin. FACEPLATES: 1" x 2-1/4" round corner. STRIKES: 2-1/4" full round corner. BOLT: 1/2" throw. HANDING: Reversible for right or left hand doors. ANSI/BHMA: Grade 3. Locksets with "SmartKey" (denoted SMT) feature allows, in 3 steps, locks to be re-keyed to a spare set of keys. When the spare keys are done being used, the lock can be re-keyed back to the original set of keys; can continually be re-keyed.