Atlas Satin Chrome keyed entry tulip knob with extra deadbolt and 4 keys. All-metal construction for optimal durability; all keys work with both locks. Backset (distance from the edge of the door to the center of the doorknob) adjusts from 2-3/8 to 2-3/4 inches for plenty of clearance. Includes complete instructions for easy installation. - 10-year mechanical warranty. - Easy installation, all-metal. - Entry hardware installs on exterior doors, and includes knobs or handlesets (handle with deadbolt) that lock with keys or touch pads from the outside and turnbuttons from inside. - A deadbolt lock optimizes security. Lewis Hyman Atlas Satin Chrome Tulip Door Knob Combo Lock: Atlas Tulip Door Knob Combo Lock Satin Chrome - Home Security