Lang Tools TU-32-20 Compucheck Fuel System Pressure Test Gauge Check fuel system pressure on diesel engines with a Compuchek test port Fits Compuchek test ports on Cummins diesel engines as well as other diesel engines that have been outfitted with the Compuchek test port Consists of a hose assembly with a female Compuchek fitting on one end and a 3-1/2", 300 PSI gauge on the other