... tool-Vacuum&Fuel pump pressure test kit 90mm gauge Diagnosing leaks in fuel line,vacuum chokes,heating&valve ... 3 1/2" (90 mm) diameter gauge indicates both pressure and vacuum Gauge face illustrates normal and abnormal operating ranges, ... pump functions Includes: 3-1/2" (90 mm) compound gauge (readings indicated in psi, kg/cm2, in. Mercury (Hg ... Hg) Auto tool-Vacuum&Fuel pump pressure test gauge set