Material: Made of high quality plastic + metal, durable. Function: It can quickly and easily diagnose whether the car ignition system is working properly. Avoid fire, ignition coil burning, etc. The test shows that the normal spark plug is "blue purple, straight line two centimeters long", if it is red or bent, it means the ignition coil is bad. Application: Suitable for all internal combustion engines, cars, trucks, motorcycles, chainsaws, trimmers, snow blowers , generators, etc. Package includes: 1 x Spark Plug Tester with Cable. Coil Tester Coil Ignition System Diagnostic Test Tool Adjustable Auto Electric feature: Just connect spark plug and spark plug wire and screw set can quickly and easily adjust the spark gap. It can quickly and easily diagnose whether the car ignition system is working properly. Avoid fire, ignition coil burn etc. The normal spark plug is purple blue, two centimeters long straight line, if it is red or curved, it means the ignition coil is defective. Suitable for all internal combustion engines, cars, trucks, motorcycles, lawn mowers, chainsaws, trimmers, snow blowers, generators, etc. Material: plastic + metal Color: black Jumping distance: 0.8-1.5cm Package includes:1 x spark plug tester with cable