Other helpful discussions on Cock rings:

For MEN only - When measuring for a cock ring, what is the circumference around your package?
I've enjoyed using cock rings since I found EF but have almost always used the soft stretchy ones. A few months ago, I reviewed one that was made from

Best Vibrating Cock Ring?
I'm looking for a vibrating cock ring for my man that is pretty powerful to help me orgasm. any suggestions?

Flickering Touch Massage set.
I really want to try this kit, and I was thinking it'd be a great valentines day present, but I just don't know if it's REALLY worth the money. If...

Do you bring your fantasies to life?
Do you try them out in the bedroom? Do you just keep it to yourself?

Wedding Rings: Yay or Nay?
My fiance and I are getting married in about six months. He's been bringing up the fact that he needs to go wedding ring shopping for me soon. I've...

If your guy is a beginner - start with a simple 2" silicone ring. But once he gets the hang of that, he may want to try steel - check out my review for the Omega link

I'm assuming that this would be his first c-ring, so you'll probably want to stay away from the less compliant materials like metal for the time being. The most important thing to consider with a c-ring is the fit. Too constricting, it could be painful (unless that's what your going for). Too loose, it defeats the point of having it on in the first place.
In my experience, the super stretchy jelly ones tend to be comfortable, but because they are super stretchy they provide little to no constriction, thus becoming more decorative than functional.
The silicone c-rings, like the one you have shown, tend to be a popular choice for starting out. They have some stretch but are still able to provide constriction of the blood flow. Hope that helps.

I agree that if this is your first experience with a cock ring, you should go with something flexible. This ring, Beginner Cock Ring, is a great starter ring. It is silicone and pretty stretchy. Measure first to make sure you get the right size. I put measuring instructions in my review of the Barbed Wire.

I agree with Gunsmoke and Kissaki that the Omega is THE best cock ring available, but it isn't one you want to try first. As we've all said, try the silicone first, and get him used to wearing one. Then move to metal.
The Omega is like moving from one extreme to the other. It's the heaviest one I've found. Worth every penny, but may be too much too soon.

Get him used to wearing one, and work your way up to it. You won't be disappointed.

Oh... this my likely cock ring too)