AccurateDiesel 6.0L Powerstroke Billet Aluminum BLUE Fuel Filter Cap with Schrader Valve for Testing Fuel Pressure The easy way to measure fuel pressure! Built in 1/4 inch Scrader valve connects to any standard fuel pressure gauge Beautiful blue color to dress up your engine compartment This billet aluminum cap is the last fuel cap you will ever need (can be left in place permanently) - no more plastic caps that round off easily! For all 2003 - 2010 6.0L Powerstroke Diesel; Proudly made in the USA Fits the Secondary Fuel Filter located on TOP of the engine