The Kryptonite Keeper 785 is a very strong and durable chain lock made of 7 mm hardened manganese steel links. The chain surface is nylon and the padlock is vinyl-coated to prevent damage to the wheels.Newly available in 4 colors (black, gray, red and purple). 7 mm square chain links made of 3T manganese steel. New, more durable DEADBOLT mechanism. High-security disc lock body. Package includes 2 ergonomic keys. Waterproof nylon sleeve protects against scratches. Key Safe program - if keys are lost, send 1st pair of standard replacement keys free of charge. (registration required) Dimensions: 85cm chain length Protection level: 5/10 .