A Thatcham approved disc lock. 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.