[Practical Material] This product is made of aluminum alloy, which is corrosion-resistant and bright. It has good compressive strength, lightness and softness. [Application] Universally suitable for all types of 12mm spark plugs. Please check and compare fit and form carefully before placing your order. Reliable PerformanceHelps achieve perfect candle playing. Simple and convenient to use. Strictly follow the original factory standards and directly replace old or broken ones. Installation Steps 1. Simply screw the spark plug into the base of our crevice tool. 2. Measure the gap thickness using a thickness gauge of the required size. 3. Use a feeler gauge to turn the knob into position until the side electrode is compressed to the desired thickness.