I bought one of these on an A27-something cage. I have not a single good thing to say about it. It's probably okay for a few hours of play, but it kept getting hung up ion my pants seam, and no matter where I bent it, it just did not feel comfortable against my testicles. And it was a constant annoyance trying to adjust it every time I sat down or stood up. Obviously some people buy them, but I did not care for it at all.
Just pinchy and pointless. As Tom says; Maybe for some fun sex games for an hour but for normal wear forget it.
I have one of these devoces and enjoyed it to wear. The problem has been that it was from china and had a tolerance of several cm. So this ball didnt tough the tube it has been 5 cm apart. And of course the sackskin went through. So i bent it, after warming it up with a blowtorch, up into the direction of the tube. Since the skin pibched between the ball and the tibe I put something inside to avoid the skin sliding in. I think it looks good and alsdo feels good. I liked this separation and my lady to play with the balls. Nice side effect you dont pee on you balls all the time