Stores & reflects your body heat for soothing relief. Helps to improve circulation and ease stiffness, pain and discomfort. The knee supports provides firm support for your knee. Bamboo charcoal fiber releases far infrared ray to improve blood circulation, while keeping the body warm and maintaining body temperature. The structure of Bamboo charcoal provides natural minerals which absorb moisture, prevent bacteria growth and reduce odor, disrupting the spread of germs and fungi harmful to the body. The bamboo charcoal yarn can be washed multiple times.