Heh! BulgingDave,
I looked at your gallery photos, but couldn't determine the size of your balls, so I don't know if my favorite rubber donut will fit you satisfactorily. I searched and experimented over the years and found the one that works the best for me, although sometimes I wish I had a slightly thinner one than this one. I have several and have had thoughts of selling them, because I enjoy it very much for how it feels & looks when I am out and about how excited I get with it on during any sexual activity. The size of this all-rubber donut is: about 47mm ID X 82mm OD. The round thickness is about 18mm, so you see, this is a pretty good sized unit, maybe best for average-sized or smaller cocks & balls, because it gives a lot of "lift" to that bulge in the pants.
Putting a ring on and removing it can also be a little tricky, but with a little careful practice, you will probably even figure out how to do it without any lubricant. I like body gel, lube jelly, or silicone lube, which are all skin and rubber safe. I insert my balls in the "lubed" donut hole first (one at a time), if you have more than three, everything isn't going to fit into the 47mm ring (lol). You can push them in or reach through the donut hole and pull the ball-sack through to guide in each testicle (one should follow the other like a good little soldier, lol) now, if by this time, your cock is fully erect, you must calm it down a bit in order to push it into the donut hole. The inserted balls should move out of the way when the penis is inserted. Grab your cock and pull it in snuggly while pressing the donut against your pubes. Rinse everything off with water or soapy water if necessary. Removal is pretty much the reverse of putting it on; push and/or pull the penis out first then decide which testicle gets to come out next. Hope you enjoy every minute, but you should "test" how it feels when you are aroused and know for sure if it feels like it will be within your comfort zone when you get really excited. It could be too restrictive (if not painful) and interfere with ejaculation and or retain an erection beyond a safe amount of time.