Male Chastity,
This is quite an old subject really and does date back a considerable time. The two shown above are by far the most effective. There are other variants around some are total cages. I think they make for a facinating conversation piece,
In reality to object of this device is that it is wron in day to day live...in public. It also has the effect of denoting ownership. It is a device for restricting the activity of a sub.
Looks like a lot of fun to be.
Cheers
BigM