Motion Pro 08-0460 Spark Plug Gap Gauge Wire gauge type gapping tool for precise measurement of electrode gap Two electrode adjusting tools Six standard sizes - 0.025 inch, 0.030 inch, 0.034 inch, 0.035 inch, 0.040 inch and 0.045 inch Six metric sizes - 0.64 millimeter, 0.76 millimeter, 0.86 millimeter, 0.89 millimeter, 1.02 millimeter, 1.14 millimeter