Transponders are Mandatory in all Regular classes at Humberstone. Check out the link to AMB timing for the subscription that is right for your race team! http://www.mylaps.com/en/products/car-flex-subscriptions/604 Flex Transponder subscriptions offer warranty and Insurance for your subscription term. Warranty covers and defects, and insurance cover almost everything except loss or theft. 1, 2, and 5 year terms starting at $100 USD per year, that is under $10 per race weekend.