Kryptonite Keeper 12 Standard U-Lock w/ Flex Cable 004370The Kryptonite Keeper 12 Standard U-Lock w/ Flex Cable has a 12mm Hardened Steel Shackle to resist hand tools. There is a reinforced collar over the key way to further resist tampering. The High Security Disc Cylinder’s rugged design has a click style transportation bracket to make it easy to carry. There is a protective vinyl covering to prevent scratches on your frame from the lock.720018004370