The Coil-On Plug and signal probe wand catches the ignition waveform of a vehicle’s petrol engine and through this ignition waveform it opens a door into what is happening in the engine’s  combustion chambers and ignition systems. 
It determines: If the ignition plug needs to be replaced or cleaned. Does the fuel injector in the fuel system have an issue?  Are there any problems with leak down of air in any of the cylinders?  Are there variant’s in the gap between ignition spark plugs?  Does the electrode shape of the ignition plug become sharp?  Is there too much oil pollution or carbon deposition on the ignition plugs?  Has the insulating property of the ignition coil and plug worn? Is there a problem in the power supply system from the battery to the ignition system?

Comes with a long 2m cable to BNC connector which fits right into any oscilloscope
including the one shown above the T-BMINI-1104.

NOTE: Needs to be used in conjunction with an Oscilloscope