I've just come across this on Aliexpress. It looks very secure but Im not sure how comfortable it would be. Has anyone tried one? https://a.aliexpress.com/_EQT7vMl
Seems to be a plastic variant of this one: https://www.chastitymansion.com/forums/index.php?threads/blast-from-the-past.46151/
I did, it was far too small. I’ve never measured my testicals, they’re probably average sized, but it really was too small to contain them and quite painful when I got them in.
I tried the metal one. Just couldn’t fit everything in it comfortably. At least not more than maybe 30 mins.
I somehow calculated the circumference of the scrotum bars and concluded it was too small for me. Confirmed by reports from others. But now I have a 3D printer and have been designing devices. Maybe I’ll get around to a proper sized version of this one.