I recently bought a 6cm metal chastity cage. I enjoy it more than my pink chastity cage as it is a lot more comfy than the pink.one, due to the smoother ring. The only issues I have with it though is that I need to wear a strap to keep it close to my body. Wearing that elastic strap though makes it noticeable when I'm wearing clothes, and the thing that is supposed to stop me from getting an stiff clitty makes it look like I have one when I'm walking around. 

The other issue is that without wearing the strap, which could possibly solve the other problem, the cage doesn't stay near my body. I may need a tighter ring, but a 45mm ring was too tight when I wore one with the pink cage. It's difficult to know what to do as the strap works and the ring isn't too tight for my sissy ovaries, but a 45mm may not work and it's an expensive thing to experiment with.