Features:
1. Health of the coil can be determined according to spark color
and flash over distance.
2. It is intuitively and easy to understand the operation of the ignition coil.
3. Alligator clip securely fastens the tester to the ground.
4. Screw assembly adjusts spark gap quickly and easily
5. Testing helps to avoid fire, the ignition coil burned out, etc.

Package includes:
1 x Adjustable Ignition Coil Tester

https://www.youtube.com/watch?v=PeGXQ0OTkvA