1. No need to remove a wire to test spark plug, ignition coil and high voltage performance. 2. When the engine starts or runs, place the pen end on the high voltage line, LED flashing indicates ignition performance. 3. High quality insulated handle, safe and reliable, used for testing spark plugs, coils and circuit breaker. 4. The end with grooves enlarges the contact area of the wire and the instrument and makes the test results more accurate. 5. High-brightness bulbs and transparent observation windows make it easy to observe the results. Specification: Features: No need to remove a wire to test spark plug, ignition coil and high voltage performance. When the engine starts or runs, place the pen end on the high voltage line, the LED flashing indicates the ignition performance. High quality insulated handle, safe and reliable, used for testing spark plugs, coils and circuit breaker. The end with grooves enlarges the contact area of the wire and the instrument and makes the test results more accurate. High-brightness bulbs and transparent observation windows make it easy to observe results. Specifications: Condition: Brand New Color: Show as Picture Material: PVC Plastic Size: Approx. 12cm/4.7in Package List: 1 * Tester Pen