The biggest problem we have encountered is this intense burning sensation under The scrotum, we get some folds and creases. This far we've tried with nothing on The skin, baby Powder and now we're trying baby oil.
He describes it as if he had chopped Carolina reaper and then smeared his balls with it. So its intense and he's in agony. Its not The kind of pain he can just walk off.
40mm rings are to small, 45mm is ok but we might have a renegade ball, 50mm is to big and ends up rattling down his leg and hits The floor with a startling clank and a very surprised surrounding.

We've found a spacer that seems to keep his balls in place with The cb. We have another all metall cage that is hinged and it gives The same reactions of The skin.
We've tried fixed rings but we cant get both his testicles through, or if we manage we dont get The penis in place. Ice, cold hands and shortly after release doesnt make a difference. Its just pure cbt in a way none of us enjoys.
We have a tight budget so we cant really take a chance with buying a new cage without knowing it Will have a decent fit, and if The burning sensation is still there it is a bit of a downer.