I, honestly, can't say too much one way or another about these rings. They are made of silicone-like rubber (but not actually silicone or TPR). They have an approximate outside diameter of 1.25", an inside diameter of .25" unstretched, but can stretch to an inside diameter of almost 2". The texture on the rings might be nice for couples; but for solo-use, it actually can be detracting and distracting to the point of discomfort.

In my case, I purchased this set as a gasket-aid and blood restriction aid for pumping. In both of these areas, the rings failed. When used as a penis ring, the silicone was a bit too tight to be comfortable or to allow orgasm when placed in front of the balls (though it did create rigidity in the base of the shaft - behind the ring), and was distinctly uncomfortable and ultimately failed when placed behind the scrotum/testicles. And when I say failed, I mean structural failure.

After about a week of using the less-painful ring (the spiral), I was trying to remove it from around my swollen scrotum (the only location with any real gain) when it suddenly snapped off. At first, I thought it had simply come off like some silicone rings I've used - clearing the testicles with a snapping feeling and sound, but remaining intact. Then, I looked down to find the ring had neatly sheared across the doughnut at one point. This was despite my being VERY careful in care up to this point - cleaning it with toy-safe cleaner, gently drying with a towel and keeping out of bright light or extreme heat/cold. So, $6.50 lasted about a week and a half with infrequent use.

The packaging claims the rings will increase girth and length temporarily, but in my experience they did the exact opposite. I suppose for some people, this might work, and the design might prove stimulating during intercourse, but ultimately I found these rings to be quite a disappointment, unfortunately. Admittedly, had I noticed these were rubber and not silicone, I would have lowered my expectations accordingly and possibly skipped outright.

One last note - the package does not actually disclose the true composition of the rings, so if you have a latex allergy, it might be best to steer clear unless you really want the promised length and girth improvement...by way of allergic reaction.