1、Universal Type: This spark plug gap tool is universal for 10mm 12mm 14mm 16mm spark plugs, you can use desired size feeler gauge for gap thickness. 2、High Accuracy: Spark plug caliper can give you the perfect gap every time. Just place your spark plug perfectly on the gap tool. 3、Recommendation: Some spark plug electrodes will rebound, which is normal for some spark plugs. If your gap target is 0.44mm, we recommend 0.42mm so when it rebound, you get 0.44mm. 4、How to Maintenance: If spark plug gapping tool gets wet, please use compressed air to dry and apply lubricant. 5、Premium Material: Made of high quality metal, sturdy and durable, increasing the service life of the spark plug gapper. Item Type: Spark Plug Gap Tool Material: Metal Fitment: Universal for 10mm/0.39in 12mm/0.47in 14mm/0.55in 16mm/0.63in Spark Plugs. Compatible with for NGK 6061, for NGK 5671A, for NGK BKR9EIX and similar spark plugs. Not compatible with 18mm thread and longer style spark plugs 1 x Spark Plug Gap Tool