In the waist I usually wear size 28, here 28-30 stands for small. It's very short, if I was a size 30 I wouldn't be able to use it. But for a waist size of 28 it's just enough.
Pros
Good belt, the only problem I found is that you have to keep tightening the belt after long time use.
Cons
I was hoping it would be a slightly thicker material but it works well.