Grade 1 security double deadbolt with SmartKey cylinder. SmartKey cylinder eliminates traditional pins and springs. Cylinder design provides instant re key functionality. SmartKey cylinder is a bump resistant, higher pick resistant lock. Included with each lock is the re keying learning tool that allows the lock to be re keyed in 3 easy steps. Fits all standard doors 1 3/4". Standard adjustable backset 2 3/8" 2 3/4". Requires 2 1/8" diameter crossbore hole and 1" diameter edge bore. Deadbolts are keyed alike in multiples of 4.