VÖLKEL VC04184 - V-Coil 115pc 1/4" - 1/2" Assorted Thread Repair KitIn the mechanical engineering and automotive sector damaged threads such as spark plugs, bolts, oil drain screw threads, oxygen sensor or exhaust mounts lead to costly and time intensive item exchange. For parts with damaged or defective threads there is a second chance: V COIL Thread Insert System Worn and damaged threads can be replaced by Inserts in just four steps. They are stronger and with the same nominal diameter as before. simple handling