1Compatibility: Fit for Powerstroke 7.3L, for Navistar T444E, DT466E and for Caterpillar 3126, 3126B, 3126E Diesel Engines 1994?2003. Works on most for Heui injectors. 2OE Number: The replacing manufacturer part number for reference is 1833564C92. Easy solution to hard start in cold without removing the injector. 3Function of Stainless Steel Washers: If the clearance between your armature plate and adapter plate is causing cold start issues, you can install the washers to increase the clearance back to .004in to .005in. 4Purpose of Solenoid Spacer Shims: Placed solenoid shims under all four corners of the solenoid (for a total of .005in), to increase the solenoid to armature clearance to near factory specs, when solenoid is energized. 5Restored Injector Performance: The high strength metal and rubber material used in this kit protects the injectors from dirt, oil, and grease that could potentially degrade their performance.