AccurateDiesel 6.0L Powerstroke Billet Aluminum Fuel Filter Cap with Pressure Test Port This billet aluminum cap is the last fuel cap you will ever need - no more plastic caps that round off easily! Includes built in 1/8th NPT fuel pressure test port - the easy way to measure fuel pressure! Proudly made in the USA For all 2003 - 2010 6.0L Powerstroke Diesel Fits the Secondary Fuel Filter located on TOP of the engine