TU-21 Cylinder Leak Detector Tester checks the amount of leakage in an engine cylinder & helps determine the source. Best used when comparing a suspect cylinder to a known good cylinder on same engine. Ideal For testing trucks & late model cars where clearance is minimal. Equipped with 2-1/2" input pressure gauge For proper leakage test setup and accurate results. Pinpoint the source of compression problems by doing cylinder leak-down tests Works with domestic and import engines Input and leakage gauges with rubberized housing Air pressure: 0-7 BAR, 0-100 PSI Brass fittings Measures leak percentage from 0-100% 1/8" NPT manifold ports ****DOES NOT HAVE INSTRUCTION & MANUAL Our products are professional auto tools. You should only purchase the tools if you are familiar with how to fix cars. Proper use of the tools are important to prevent from any unnecessary injuries. Heavy duty moulded storage case (may get dent or crack during shipping) Case color may vary.