Nate from Crazy Compression gave me some great info on their socks:
"We use 15-20mmhg which is for mild compression...anything over 20 really is to be used for medical purposes. Our goal from the beginning was to create a unique product that combined Function and Fashion and all made in the USA. Our company has over 55 years of hosiery manufacturing experience. I would say what makes us special is there isn't another company that makes something like we make with true graduated compression combining patterns, fun colors and the ability to customize 1 pair for a customer without sacrificing the performance attributes and keeping the cost very competitive. We just try and have some fun while making the world a bit more colorful."