0-30 mmHg compression socks increase circulation and help relieve varicose veins and edema. Zip design on compression stocking is easier to get in and out of with swollen or sensitive legs. Specify size: Medium (fits calves up to 16 1/2"), Large (fits calves up to 18") or XL (fits calves up to 19"). 75% nylon/25% spandex. Hand wash.