Craftsman 1 pc Spark Plug Gauge

Keep all engines, from your car to lawn equipment, running smoothly with the Spark Plug Gauge. Gapping spark plugs is an essential part of every tune-up and this tool makes it easy. Check the depth of the gap between the electrode and ground strap by sizing it against the gauge, which ranges from 0.020" - 0.100". Use the adjustment hole to gently open or close the gap. This handy tool will keep your engines running at peak performance for years to come.