The oxford magnum shackle 340 with bracket is a solid lock with great portability and mounting options the oxford magnum d lock provides the best level of security for your frame it has been accredited sold secure gold the highest rating a lock can achieve sold secure gold is bike insurer friendly the magnum features an ultra strong double locking mechanism so anyone trying to gain access to the lock with out the keys is going to have trouble also the lock is supplied with a mounting brac