For keyed exterior doors. Unlocked by key from outside when outer knob is locked by turn-button in inner knob. Packaged with a 1″ square corner, 1/4″ round corner, and 1″ circular drive-in deadlatch, adjustable for 2-3/8″ or 2-3/4″ backsets. 2-1/4″ x 1-5/8″ full-lip square corner strike. Grade 2 construction for superior durability and quality performance. Lifetime mechanical warranty.