14mm hardened MAX Performance steel shackle resists cutting and leverage attacks. Double deadbolt locking mechanism for extensive holding power. New, higher security, disc style cylinder with more than 1 million key variations. Reinforced anti drillpull cylinder protection system. Enhanced internal engineering resists twist attacks. Center key location and dual overhead cam locking mechanism resists leverage attacks. Sliding dustcover protects and extends cylinder life. Includes versatile EZ Mount transportation bracket. 3 keys one lighted with high intensity bulb replaceable battery. Anti rattle bumpers reduce noise during transport.