12mm chain with disc lock. A high security lock with innovative oval crossbar disc lock, designed to defeat thieves' maximum attacks.12mm six-sided, chain links made of hardened manganese steel for maximum strength. Durable, protective nylon cover with Hook-n-Loop fasteners to hold in place. The Kryptonite New York Chain includes the Kryptonite Evolution series 4 Disc Lock with 14mm MAX-Performance steel shackle.