Kryptonite Keeper 785 Integrated Chain Lock 000853The Kryptonite Keeper 785 Integrated Chain Lock uses 7mm four sided chain links made from 3T Manganese Steel for extreme durability. There is a Patent Pending End Link Design secures chain to hardened deadbolt eliminating critical vulnerability. The High Security Disc-Style Cylinder is pick and drill resistant. Includes two ergonomic I Keys. The Durable Weather Resistant Nylon sleeve prevents scratches on your frame.720018000853