100% Acrylic Pull On closure Acrylic Soft Seam technology creates an ultra-smooth toe seam to help reduce rubbing and irritation. Accepted by the American Podiatric Medical Association. Non-binding Soft Knit top adds 40% more cross stretch for a comfortable fit. Reinforced heel offers durability. Comfort fit design fits calves up to 18 inches. Thick, plush terry on the sole softly pads your steps. Moisture-wicking acrylic fibers keep feet cool, dry and healthy.