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. Security knobs feature full 1" solid core throwbolt, all metal mechanisms, anti-pry shield and pick resistant 5-pin system. 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: A156.2 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.