The Kryptonite Kryptoflex offers good security for moderate to high crime areas, with a standard length 13 mm hardened Kryptonium steel shackle. The patented deadbolt locking mechanism offers extensive holding power as well as the high security disc style cylinder. It has a reinforced sleeve over the crossbar and cylinder that provides enhanced security protection as well as the internal housing, which increases resistance to twisting and leverage type attacks. The offset key location and overhead cam locking mechanism resists leverage attacks along with the patented, easy to use, high security Bent Foot design.It also comes with anti-rattle bumpers that keeps the shackle snug against the crossbar and prevent unnecessary noise whilst you're out and about. It mounts quickly and easily whilst supporting the carrying of most common lock sizes.It will fit on frame tubing 25mm to 80mm whether round, oval, triangular or square shapes and the mounting system allows for 360 degree rotation, providing the ability to micro-adjust the lock angle to better fit and align with a bike frame's specific geometry.