The design house square single-cylinder deadbolt locks and unlocks with a key on one side and a twist knob on the other. Finished in matte black 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 knob on standard 1-3/8-inch and 1-3/4-inch thick doors with a cross bore 2-1/8-inch in diameter or edge bore 1-1/16-inch in diameter (1-inch x 2-1/4 inch radius corner faceplate). This product is ansi grade-3 certified, which means it is rated for residential security. Designed and manufactured by design house, the trusted source for quality lighting, hardware, plumbing, kitchen, and bath products for every taste and budget.