Deadbolt thrown or retracted by key from outside or by inside turn unit. Bolt automatically deadlocks when fully thrown. Solid 1-piece design. Provides Grade 1 features of security against hammer and crow bar prying, kick-ins, cylinder knock out attacks. 3″ screws with steel door frame reinforcer protects against violent forced entry attacks. Universal latch packaged with a 1″ square corner, 1/4″ round corner, and 1″ circular drive-in deadbolt, adjustable for 2-3/8″ or 2-3/4″ backsets. 1-1/8″ x 2-3/4″ x 1-1/16″ standard strike. Grade 2 construction for superior durability and quality performance. Lifetime mechanical warranty.