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. Requires 2-1/8" diameter crossbore hole and 1" diameter edge bore. Deadbolts are keyed alike in multiples of 4.