Medeco 11TR50310 Maxum Residential Single Cylinder Deadbolt, Satin Brass Blackened, 2-3/8" Backset, High Security Restricted M3 Keyway, Keyed Different Medeco patented technology. Top Rated Deadbolt. Uses key outside - thumb turn inside. No unauthorized key duplication. Bump and pick proof. Locks are keyed different.