5x Diesel Fuel Line Socket Set Tesmirror 17mm 19mm 21mm 22mm 24mm Flare Nut Socket Set 3/8″ Drive Diesel Injector Fuel Line Power Stroke Engines. Tesmirror line socket set features a 17mm socket compatible with multiple Audi/Volkswagen/BMW models, a 19mm socket for diesel engines from 2011 and prior including the Cummins ISB, a 21mm for Paccar MX 11 and MX 13 engines, a 22mm for the most recent ISX Cummins engines, and a 24mm for NOX and carbon smoke sensors.