Specifications Engine Spark Plug Gap Tool Universal for all 10mm,12mm, 14mm spark plugs magnetic screwdriver included This Spark Plug Gap Tool will give you that perfect gap every time. No more banging the plug tip on random surface to close it & then use a coin gap to open it back up. Do it once with precision with our tool. Easy to use steps: Simply screw your spark plug into the bottom of our gap tool. Use your desired size feeler gauge for gap thickness. Turn the knob with the feeler gauge in place till the side electrode compresses to the desired gap thickness. - 6061 Billet Aluminum - CNC machined - Matte Black - Fits all 14mm Spark Plugs - Limited Lifetime Warranty Applications: Universal for all 10mm,12mm,14mm threaded spark plugs Spark Plug Gap Tool will give you that perfect gap every time. No more finding something to bang the spark plug on and having to test it over and over till you got it just right. Do it once with precision with our tool. Here are three sizes for you to choose: 10mm, 12mm, 14mm.. They are exactly the same except for different thread sizes. Click to see more