Disc lock with case-hardened 1/2 inch Kryptonium steel shackle for maximum security 14 mm hardened MAX-Performance steel shackle resists cutting and leverage attacks Double deadbolt locking mechanism for extensive holding power High security, disc style cylinder with more then a million key variations Reinforced anti-drill, anti-pull cylinder protection system Sliding dustcover protects and extends cylinder life 3 keys: one lighted with high intensity bulb and replaceable battery colour: black with white graphics Approved to Thatcham CAT3