The Kryptonite Evolution Mini-5 U-Lock features a 13mm hardened maximum performance steel shackle and features a double deadbolt anti-rotation design that resists bolt cutters and torsional leverage attacks. Disc style cylinders with center keygroove lock are protected with vinyl coating to resist picking and drilling. The keyway has a sliding dust cover to protect the cylinder from dirt and debris when not in use. Includes three stainless steel keys with an ergonomic design that reduces torque and prevents bending or breaking. One key has LED key fob to increase visibility in the dark. Rated as 7/10 in our security scale, the Evolution Mini-5 is ideal for quick stops on college campus, several hours in major metropolitan areas, all day & overnight in neighbors and rural areas. It also comes with a patented FlexFrame-U bracket to provide convenient multi-location U-lock movement. With these great features and our support programs that include key safe, anti-theft protection, and lifetime time, Kryptonite Bicycle Locks are the best choice for protecting your valuables.