The sizing options in this set turned out to be more useful than I expected. I used two rings combined at the base and got a noticeably firmer, longer-lasting erection. The material feels comfortable enough to wear for a while.
The different sizes in the set let me mix and match depending on the day, which I didn't expect to matter as much as it does. Wearing one at the base definitely made a difference in how long I lasted, and the fit stayed comfortable the whole time.
Wasn't sure about the sizing at first, but wearing one at the base and a smaller one on the testicles at the same time made a real difference in how long I lasted. The material has enough give that it doesn't pinch, which was my main worry.