For keyed exterior doors. Both levers locked or unlocked by key outside or turnbutton inside. All metal components. Solid steel deadlocking latch assembly. Rust resistant solid brass keyway for more security. Seamless one-piece lever for extra strength.DOOR PREP: 2-1/8" Crossbore, 1" Edge Bore, 1" x 2-1/4" Latch Face. DOOR THICKNESS: Fits 1-1/4" to 1-13/16" doors. CYLINDER: 6-pin, removable SC1 keyway, solid brass, one piece; re-keys to Schlage. With 2 nickel plated, solid brass keys. FACEPLATES: 1-1/8x 2-3/4 STRIKES: 1-1/8" x 2-3/4" square corner T-strike. BOLT: Steel 1/2" throw. HANDING: Reversible for right or left hand doors. Please follow installation instructions carefully. ANSI/BHMA: Exceeds Grade 2 Standards. U.L. Approved 3-HourFire Rating.