Yes the goal is to get stiff enough for sex
The goal then is to successfully pump to a good stiffness then add the proper size and/or number of rings to maintain that stiffy when the vacuum is released.
This usually takes a medical grade VED. I use an Encore Deluxe, so I am more familiar with that particular brand than others.
The first step is to practice pumping. Go slow and stop frequently to allow the blood to flow into your dick to compensate for the reduced pressure. Stop when you feel discomfort. Let off the vacuum, pause and repeat. Eventually the process can become almost routine. The next step is to experiment with rings. I find 2 Osbon rings work perfectly for me for penetrative sex.
The caveat is the restriction can ONLY be maintained for about 20 minutes before the ring(s) should come off.
I found this advice from a wife. Her description of her husband's practice sessions were good. I would only add that if one ring is not sufficient and you go smaller in ring size and that still doesn't do the trick, try adding a 2nd ring. I have found 2 Osbon rings will fit on my Encore and can be added as easily as one.
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