I'm sure many readers tire of hearing from me!
--But, I try to speak up when I think I can help someone, though---especially through personal experience. I'm really no expert, 'just have learned from trial and error.
I have used cockrings (mainly in my early PE program) and I much prefer the leather straps with snaps or velcro. EASY to attach and remove as needed.
I purchased a set of the "professional" rings (molded flesh-colored rubber). There are a number of these "professional rings" available but mine happened to require an accompanying special tool to apply and remove them. The rings proved to be trouble.
Not only were they difficult to fool with (ESPECIALLY removing!) but I unknowingly used one of the too-small sizes which started out "feeling good" but over time caused me real concerns. I finally got the thing removed but had to live with a bad indentation (to the shaft near where it exists the abdomen) for quite awhile. Jelq finally (I guess) helped "correct" the shaft unevenness.
But, that "correction" took a very long time to achieve.
I stayed plenty worried.
Guys, just be careful with getting the proper size ring and pay attention to how you feel in it. If you notice numbness, a pronounced "burning" sensation, coldness, or a graying (bluish) discoloration beginning in your penis---remove the ring el-pronto fast. DON'T take (foolish) chances. If circulation is cut-off (for too long) in the penis, it is dangerous business. I found "my symptoms" of wrong-sizing both physically painful but more so emotionally. I panicked, really. I even started fearing the very worst outcome--amputation. I really did have one "sick-looking" penis for several minutes having worn a too-tight ring. I had the numbness, the discoloration, and the total limpness....NO feeling whatsoever. I was plain 'ole horrified. Time stood still, I was so frightened.
Guys---I'm not discouraging anyone from ever using a ring...it's just correct "sizing" of these rings is crucial.