The Big Boss ultra strong alarm disc lock is the strongest, most secure lock Oxford have ever manufactured. Featuring a thick 16mm shackle, the Big Boss disc lock can be used as a disc lock or can be combined with a chain and used as a padlock. Featuring an audible alarm that produces 100dB of sound that can be heard 500 metres away when the lock is tampered with, the Big Boss is the ultimate thief deterrent. The Big Boss is also water, vibration, frost and heat proof, so it can fend off the elements too. The Thatcham Institute for Vehicle Security is recognised by insurers as the UK’s leading tester of vehicle security products. Products with the Thatcham label have been demonstrated to comply with The British Insurance Industry’s Criteria for Vehicle Security - the toughest set of standards ever to be applied to motorcycle locks and alarm/immobilisers. As a result, many insurance companies offer significant discounts to those who use these Thatcham Approved Products.