Features and Benefits: This Three-Way tester allows quicker and more accurate testing of exhaust blockages in catalytic converters, mufflers, etc.; The 2-1/4″ special gauge has two multicolored bands for measuring at Idle and 2500 RPM. The scale ranges are in PSI and bar. Boot included on gauge for extra protection.; Hose is 6 feet, enough length for the Technician to test from the drivers seat.; Can test in THREE different places: Oxygen Sensor, Exhaust Pipes, and Air Injection System.;