The Kryptonite new York legend chain features massive 15mm round chain links made of 3T hardened steel with a protective nylon cover held in place with hook-n-loop fasteners. The new York disc lock features 15mm hardened max performance steel shackle with a double deadbolt anti-rotation design that resists bolt cutters and twisting leverage attacks. The lock also features a patented hardened oval crossbar design that is stronger a typical round tube. 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. Rated at 10/ 10 on our security scale, The new York legend 1515 15mm chain & New York lock 15mm disc lock is Good for quick stops in major metropolitan areas and all day & overnight on college campuses, suburbs, and rural areas. 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.