Hook n Loop fasteners to hold the nylon cover in place. 14mm six sided chain links made of 3t maganese steel. 15mm hardened MAX Performance steel shackle. Hardened double deadbolt design gives additional protection against twist attacks. Patented, hardened oval crossbar design is stronger than a typical round tube. New York Disc Lock with higher security disc style cylinder. Includes 3 Stainless Steel keys 2 new I keys and one with a high i ntensity LED bulb for convenient, easy unlocking in the dark.