13mm shackle. Sold Secure Silver and VDS Class A approved. New upgraded Kryptonite Evolution U-lock for moderate to high theft areas. Tough 13 mm case-hardened Kryptonium Steel shackle resists cutters and leverage attacks. Centre keyway location deters leverage attacks. Secure, disc style cylinder resists picking and drilling. Patented deadbolt locking mechanism. Supplied with bracket for carrying on the bike