1. Enables technician to test exhaust back pressure through oxygen sensor.

2. Oxygen sensor adapter includes M12 and M18 thread.

3. The special 2-1/4 in. gauge has two multi-colored bands-idle 2500RPM; with pressure shown in PSI and bar.

4. Fumished with rubber boot to protect gauge.

5. Hose is 6 ft; enough length for the technician to test from the driver's seat.