This single cylinder deadbolt can be locked or unlocked by key on the outside and turn button on the inside, and it''s ideal for exterior doors such as front doors, garage doors, and side doors. Adjustable latch fits 1-3/8" 1-3/4" thick doors and 2-3/8" 2-3/4" adjustable backset. Comes with 2 keys and in 4 different finishes to match any home.