With 5.5mm thick security heavy-duty chain links, our bike chain lock is made of heavy-duty steel known for its cut-resistance. The chain lock itself is made of electroplated brass and hardened stainless steel shell, which cannot be defeated with any normal burglary tools. Our motorcycle lock comes with 4 rust resistant brass keys. You can take one of the keys to use in daily life, and you can leave another keys at home in case you accidentally lose one. Our bike lock is the ideal thing you need for the purpose of safely and securely locking the bike at the time of parking it in an open area. Specification: Color: sliver Size: 50 cm Material: Alloy steel, Hardened steel Package: 1 × Bike Chain Lock 4x brass key