Enables boring out ragged and tightly stuck glow plugs as well as for re-cutting and cleaning the original M8x1 glow plug mounting thread, and for maintenance by extending to M10x1 and consequent insertion of a M10x1 to M8x1 threaded bushing.
The new glow plug will then be screwed in the cylinder head together with the threaded bushing. The compressed air adapter included in the set prevents contamination from getting into the combustion chamber.