Delaney LU Series Grade 2 Double Cylinder Deadbolt Features: Grade 2 UL 3 Hour Fire Rated SC4, 6-Pin Keyway Protection Sleeve Free Spinning Cylinder Collar Hardened Steel Rod Latch Insert Specifications: Backset: 2-3/4 UL Latch standard, 2-3/8 optionalDoor Thickness: 1-3/8 ~ 1-3/4 door standardInterchangable Core: Optional small-format 6-pin availableStrikes: 1-1/8 x 2-3/4 (9111). Includes reinforcement plateScrews: Combination screws that suit both wood or metal door mounting. Includes 3 Security Screws Door Prep: Cross bore: 2-1/8 Edge bore: 1 Latch face: 2-3/4: 1-1/8 x 2-1/4. 2-3/8: 1 x 2-1/4 Latches: Deadbolt: 2-3/8 & 2-3/4 adjustable (9091 UL) Faceplate: 1 x 2-1/4 square corner Bolt: Full 1 throw. 3-Hr. Fire Rating