AccurateDiesel 6.0L Powerstroke BLUE Billet Aluminum 2 Piece Cap Set - Fuel Filter and Oil Filter Caps with Pressure Ports These billet aluminum caps will be the last you will ever need - no more plastic caps that round off easily! Bright blue color to dress up your engine compartment; Proudly made in the USA For all 2003 - 2007 6.0L Powerstroke Diesel (Trucks only) Fuel Cap (fits secondary filter on top of the engine) includes 1/8th NPT pressure test port - the easy way to measure fuel pressure! Oil Cap also includs pressure port for measuring oil pressure, temperature, or connecting a bypass oil filter system.