The system sucks out the air under the waders creating a partial vacuum with each breath that air slowly fills back between breaths.
When I am close to cumming the breaths get quick and replenishment isn't as complete - thus I get a very near to asphyxiation experience.
I also post pics from the Internet on that site and have thousands of photos dealing with heavy rubber, latex and wetsuits. I used to live in Washington State and enjoyed wearing my latex outside in the rain we regularly had. I have since retired and my old collection has seen better days.
The waders suck down tightly to me with each breath as well.
The partial vacuum created by the sucking of air pulls new air between the waders and the inner suits.
The new suit is everything I expected as seen in my most recent photos and videos.
I have always wanted a suit with watertight closures and completely isolating from the outside world.
When I turned about thirteen I learned what those feeling were and I was forever hooked on rubber.