Bicycle security for moderate to high crime areas, with a standard length shackle 13 mm hardened Kryptonium steel shackle Patented deadbolt locking mechanism for extensive holding power High security disc style cylinder Reinforced sleeve over crossbar and cylinder provides enhanced security protection Reinforced internal housing increases resistance to twisting and leverage type attacks Offset key location and overhead cam locking mechanism resists leverage attacks Patented, easy to use, high security Bent Foot design Anti-Rattle bumpers keeps the shackle snug against the crossbar and prevent unnecessary noise 2 keys The Transit FlexFrame-U mounts quickly and easily and supports the transportation of the most common u-lock sizes The Flex Frame-U fits bicycle frame tubing 25mm to 80mm whether round, oval, triangular or square shapes Rotating dustcover over cylinder protects from dirt and grime Vinyl coated and weatherproof U-lock dimensions: 8.2 cm x 17.8 cm x 13 mm Approved to bicycle Silver Sold Secure standard