Brian,
It's not necessarily intuitive when you're accustomed to the way that the pneumatic squeezers work. I'll try to, very briefly, explain the differences:
Pneumatic, traditional squeezers operate with you setting the travel of the ram. You have to readjust the travel for different lengths of rivets.
Numatx squeezers are COMPLETELY different. Numatx squeezers are adjusted by setting the pressure on the air supply. The air pressure acts on a hydraulic cylinder to close the ram, but just ignore that statement.
The important thing to know is that the Numatx squeezes the rivet based on pressure. What that means is that when the squeezer exerts XXX psi on the rivet, and the force required to squash the rivet to that point equals XXX psi, the squeezing stops. It stops right there, every time, very uniformly.
With the Numatx, you only need to know how many PSI are required to set a 3/32" rivet or a 1/8" rivet. This is dependent on your gauge, simply because gauges vary slightly. Once you know those numbers, you only need to set the air pressure input and rivets simply come out uniformly....regardless of length!! Only the rivet diameter affects the outcome. It's actually super simple once you do it.
Blake has the Numatx squeezers on his site:
https://www.flyboyaccessories.com/product-p/2701.htm