Keeper 712 hardened steel chain lock

Updated 2026-09-05

With a 4ft length, this chain lock provides the extra reach needed to secure a bicycle to large or awkwardly shaped objects. The 7mm four-sided chain links are made from 3t manganese steel, offering a high level of durability and resistance to manual cutting tools. It is a versatile choice for daily commuting.

The integrated lock head features a high-security disc-style cylinder that is designed to be pick and drill resistant. The hardened deadbolt provides superior holding power, ensuring the chain remains securely locked under pressure. The design is streamlined to make the locking and unlocking process as simple as possible.

A weather-resistant nylon sleeve protects the chain and the bicycle, preventing metal-on-metal contact that could lead to scratches or rust. The lock includes two ergonomic stainless steel keys. This chain is a reliable and flexible security option for riders who need more length than a standard U-lock provides.

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