The Kryptonite Evolution Mini-5 U-Lock features a 13 mm hardened max performance steel shackle with a double deadbolt anti-rotation design that resists bolt cutters and twisting leverage attacks. The lock's disc-style cylinder with center keyway is protected by a vinyl coating and is pick and drill resistant. The keyway also features a sliding dust cover to protect the cylinder from dirt and debris when not in use. It includes three stainless steel keys with an ergonomic design to reduce torque and keep them from bending or breaking. One of the keys has an LED key fob for added visibility in the dark. Rated at a 7 / 10 on our security scale, the Evolution Mini-5 is good for quick stops on college campuses, a couple of hours in major metropolitan areas, and all day & overnight in suburbs and rural areas. It also includes our patented FlexFrame-U Bracket providing convenient multi-location U-Lock transport. The combination of these great features and our support programs including Key Safe, Anti-Theft Protection, and Lifetime make Kryptonite Bicycle Locks the best choice for protecting what you value.