1. Wide ApplicabilityThrough exquisite craftsmanship, we have extended the threaded rod to a deeper length, making this version of spark plug gap gauge suitable for 99% of spark plugs in the market, with increased universality. 2. Universal Spark Plug Gap ToolSpark plug gap tool with feeler gauge is designed for spark plugs with 10mm, 12mm, 14mm, and 16mm sizes, specifically for shortthreaded spark plugs used in small engines such as chainsaws, trimmers, and other equipment. 3. Precise Measurement Some spark plugs may experience electrode gap rebound, so we recommend using a measurement value that is 0.002 0.004 inches less than the target value. For example, if you want a 0.016inch gap, we suggest using a measurement of 0.012 0.014 inches, so that when it rebounds, you will achieve a 0.016inch gap. Simple and efficient. 4. Easy to UseSimply place the spark plug into the universal spark plug gap tool, insert the feeler gauge with the desired gap thickness, rotate the knob until the electrode is compressed to the desired gap thickness. Very easy to use.