Kit is designed to repair glow plug threads for a wide range of diesel engines; It professionally and permanently replaces the threads on modern vehicles which have very little space and access to glow plugs; The Kit includes self-guided reamers and taps with no need for glue or thread seal; 4 of each thread repair inserts are included; Sizes: #7731 - M8 x 1.00 (Short); #7732 - M8 x 1.00 (Long); #7733 - M9 x 1.00; #7734 - M10 x 1.00; #7735 - M10 x 1.25