1. Material: zinc alloy 2. Product size: diameter 37.5mm, thickness 3mm. 3. Indication: Both sides are printed with metric system. 4. Function: The round hole is used to adjust the spark plug, and can also be equipped on the key ring. 5. How to use: Insert the edge of the coin into the ignition gap of the spark plug to measure and adjust 6. Use size: Metric system 0.6-2.4 (0.50-2.50) mm; inch system 0.020-0.100 inches
