I used one once and it was kind of strange, when I got fully hard I felt like I was going to explode.
What happens is when the blood goes in to your hard cock the ring holds a lot of it from going out which made my cock feel like it was going to explode, almost, no it did, it also hurt some and I did not care for it, neither did the wife, she did not like me having it on when she was giving me head. From what I have heard it should prolong you from cumming make your cock bigger then normal and then let you cum harder. I never got that far as it did hurt and we stopped and removed it.
There is my story with one...

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