Spark Plug Tester Dual Hole 12V Ignition Coil Tester with Adjustable 500-9000 RPM. Quickly test spark plug performance with this dual-hole tester, simulating engine RPM from 500 to 9000 RPM. It works with most 12V gasoline vehicles, featuring adjustable test holes, LED digital display, and easy 12V battery power connection for fast, accurate diagnostics.
