Ergonomic measurements?

[Razzamattaz]

Hi,

I’m wondering how you’d measure for an ergonomic ring. In this case the x3s rings. I’m normally around 57mm on a circle. So do I just get the one with a 57mm equivalent circumference or what?

Thanks.

[Naljeans]

Yes, I believe that is the normal standard. The oval rings don’t work well for me but I recall the fit being the same size as the O rings.