(Back Tap Spark Plug Thread Repair Tool 14mm 12mm 18mm 10mm 8mm M8 M10 M12 M14 M18 Thread Chase Tap Kit. Specifiction: It contains 7 tools, include 8mm, 10mm, 12mm, 14mm, 18mm back tap, detail size is: " length); " length); "length); "length); " length); " length); " length).