My old cheap Chinese chastity cage had a 45mm diameter ring so I assumed that's what I needed from Holy Trainer. I didn't bother following their sizing instructions.
|Holy Trainer 2 rings are... oval.|
The answer, of course, is that the Holy Trainer 2 rings are... oval. The measurement they use to describe them is across the shortest distance!
On its own the circumference doesn't tell us much, it's the cross section that matters.
You can get the area of an oval using the following calculation:
Assuming all the Holy Trainer rings have the same proportions as my original 45mm HT2 ring, you get the following areas:
Old style circular rings like on my Chinese chastity cage are of course Pi * R * R. This gives us:
They are all a bit tighter than the Holy Trainer equivalent. The take home here is follow the manufacturer's instructions and measure your tackle with a bit of string!
However I can tell you from personal experience that a 45mm circular ring fits me comfortably and that my most comfortable Holy Trainer 2 ring is the 040. Your mileage may vary...
Chastity is more fun when your partner is involved ! Why not introduce some Female Centered Femdom to your relationship?