The Aetrex Compression Sock with Copper Sole Technology is unmatched in comfort, performance, and protection. The lab tested and clinically proven Copper Sole Technology prevents bacteria, fungi, odor and improves skin texture and appearance. It has a graduated compression from ankle to knee (20-25mmHg) and has hand-linked flat toe seams. Compression socks reduce swelling and leg fatigue and are recommended for varicose veins, swollen legs, post-surgery, and moderate edema. Medium fit about a men's shoe size 7 to 10, the large is for sizes 10 to 12 and the extra-large is for men's shoe sizes 12 to 15.