The Lang TU-15-8 diesel adapter (which features a 7/8" injector fitting) iS designed for use with the Lang TU-15 compression tester on the following Cummins engines: Cummins V-185 Cummins V-210 Cummins V-225 Cummins V-555 Cummins VT-255 Cummins VT-555 New open box.