Oxford - Hd Mini U-LockMini U Lock is a tough and compact lock that has been independently approved and awarded Sold Secure Bicycle DIAMOND & Motorcycle GOLD. This lock has a key replacement service so that if you are unfortunate enough to lose all your keys a new one can be made up. Just remember to take note of your key number and keep this in a safe place. Key Features: Tough hardened steel lock 14mm ? shackle Compatible with chains up to 16mm Double locking mechanism