This Therapeutic Knee Warmer is made of a wool blend that generates soothing warmth against cold, chills and arthritic pain. Gentle ribbed compression helps stimulate blood flow and accelerate healing. Soft, stretchy knit for a comfortable, snug fit. Easily slips on and off. Acrylic/Wool/Polyester/Spandex. Unisex. One size fits most, left or right knee.