I've looked a bit at it(I didn't knew it),and it seems to be a piercing in the penis(and maybe a part going in the urethra,not sure),connected to the cage,making impossible for the wearer to take it off without the cage is unlocked and the "prince albert" part removed from him.
Firstly,my twin would not want it at all.And I doubt my parents would make him wear one,anyway.
Even more as piercing are forbidden(except for me,I had my ears pierced,accepted by my parents),even if I asked a lot to be allowed to have my navel pierced(it can be pretty sexy).Tattoos are,of course,forbidden too(and I would like to have some...).
I've read a bit about people able to take their penis out of the cage,even if locked.But it isn't the case for everybody,and,often,they can't put it back in again,which would means a lot of trouble and restrictions for my twin,if caught with his penis out of the cage.
And it won't help about the pain and possible health problems after wearing it permanently until married.