A lightweight integrated chain in the keeper line of kryptonite security products Features: The keeper integrated chain is a hardened triple heat-treated boron manganese steel chain made with 7 mm four-sided links the keeper integrated chain secures with a new integrated lock head chain links are enclosed in a nylon-webbing sleeve to protect paint from scratches end pin-link design secures the chain with the hardened deadbolt offers great holding power against attacks high security disc-style cylinder is pick and drill resistant recommended for use in low crime areas comes with 2 ergonomic 'i' keys the new 'i' key makes opening a disc-style cylinder much smoother 85 cm length approved to bicycle silver sold secure standard