Speed-Autoparts-Usa Universal Matte Engine Spark Plug Gap Tool Gapping Gapper 10mm/12mm/14mm/16mm. Type: 10mm 12mm 14mm 16mm Engine Spark Plug Caliper Gapper. Use your desired size feeler gauge for gap thickness.Good Compatibility,Spark plug gap tool is compatible for NGK 6061, for NGK 5671A, for NGK BKR9EIX and similar spark plugs.