Fuel cap with clear brass top and clear 6061-T6 Aluminum lower. Vented. Right hand threaded. Knurled for extra grip, for easy on-off with or without gloves. The lower threaded part of the cap has a spring-bound valve system, centrally located in the middle of the bung. This connects to 3 vents in the top part of the cap to allow alleviation of any pressure or vacuum that may build up inside the tank. The O-ring seal, that sits on the top of the thread, offers a secure seal.