The Design House 581850 Single Cylinder Deadbolt locks and unlocks with a key on one side and a twist knob on the other. Finished in brushed bronze and designed for left or right hand doors, this deadbolt fits the two most common backsets in the U.S. (2-3/4-inch and 2-3/8-inch). This deadbolt is commonly used on front doors and back doors. Use this deadbolt on standard 1-3/8-inch and 1-3/4-inch thick doors with a cross bore 2-1/8 in dia or edge bore 1-1/16 in dia. (1 in. x 2-1/4 in. radius corner faceplate). This product is ANSI Grade-3 certified, which means this deadbolt is rated for residential security. The Design House 581850 Single Cylinder Deadbolt comes with a 5-year limited mechanical and finish warranty to protect against defects in material and workmanship.