Silisleevs work a great job at providing a scuba diver-like suit around the penis during a pumping or
bathmate session.
Silisleevs as I have used them myself in the
bathmate, provide a more uniform distribution of the pressure across the entire penis, with massive reductions in fluid retention or FR.
You can wear the
Silicap aswell.
Doing this, one can take higher degree of vacuum, but always work to it, don't go overboard.
I don't know what the original
pump sleeve was that was mentioned earlier in the thread, but it has nothing to do with the Silisleeves or
Silicap.