Controlled compression assists the muscles in pushing the venous blood up the legs back toward the heart. Improved circulation reduces leg fatigue. Men's medical socks are fashioned with controlled compression, which assists the muscles in pushing the venous blood up the legs back toward the heart. Improved circulation thus reduces leg fatigue. In addition, they meet the needs of the active man. Provide long lasting support for the most demanding of lifestyles. 10-15 mmHg. Small/Medium fits shoe size 5 - 10, ankle 7 - 10 inch, calf circumference 11-1/4 - 15 inch.