Oxford OF32M Block Monster Ultra Strong 11 mm The Oxford Monster disc lock boasts a hardened 11mm Ni-Cr-MO da alloy steel arch with double closing mechanistic and two hardened steel balls. Designed with ample disk access to allow for pieasy mounting. It can also be used with a chain as a lock. The lock has a sliding dust protection system. The blocker has da key replacement service: in case you're tu so unlucky to lose all le keys, we'll give you whole new one. Just remember to take note of your key number and keep it in a safe place. Tested and approved across Europe: Sold Secure Motorcycle Gold Thatcham Vehicle Security