SMALL!
I wear large pants. Not XL or XXL, just L. So I ordered L thinking that would work. Not even close! I should have ordered a XXL at least. Fortunately I have a velcro extension from another brands L that I've never used because I didn't need it. I grabbed that extension and it worked with this. Now that I can wear it, the plastic supports are really good and the whole thing is quite comfortable. Best part is it's not like others that will make your midsection sweat to death, as it's actually breathable.
Rating: 3 stars