These Steeda Spark Plug Gapping Tools are Specifically Designed for the Ford 3-Valve Cylinder Head Spark Plugs. Steeda Manufactures these Spark Plug Gapping Tools from Quality Materials to Ensure Accurate Spark Plug Gapping. These Tools Feature a Built-in Set Screw to Allow for Fine Adjustments to your Spark Plug Gap. They are Great for Enthusiasts with Supercharged or Nitrous Applications.