Snap on something?

I have 2 of the Snap on ones. I have found a plugged jet in a carb. by doing a balance test. They are really nice to use if you have learned the different ways to test things. This is what I have.
Snap-On Counselor Digital Oscilloscope MT1665 with cords, and book | eBay
This looks like yours.
Vintage Snap On MT655 Engine Analyzer | eBay