Compression for tired and aching legs, swollen legs, minor fatigue, minor heaviness. Graduated compression has been proven effective in the prevention and treatment of venous disorders. The compression of the hosiery is greatest at the ankle and decreases as it moves up the leg. Graduated compression helps to improve circulation and valve functioning. 30-40 mmHg. Medium fits ankle 8 - 8-3/4 inch, calf 12 - 15 inch, calf length 14 - 17 inch.