Thermoskin arthritic knee wrap is ideal for arthritis. The thermoskin knee wrap stimulates blood circulation, promoting relief from arthritic pain while you perform your daily routine or while you sleep. The wrap provides gentle compression and warms the surface skin, facilitating blood flow throughout the knee to reduce swelling, improve the mobility of joints and ligaments, and helps relieve arthritic pain. The wrap is made from a flexible nylon/neoprene material that allows a full range of motion, and fastens with an adjustable hook-and-loop closure for a personalized fit and compression variation. Trioxon advantage: thermoskin's exclusive trioxon lining is soft and comfortable against your skin.  Trioxon captures your natural body heat for therapy and pain relief.  The three dimensional trioxon lining provides insulation and wicking of moisture via air circulation.  This allows the skin to remain well oxygenated and comfortable for extended periods. Clinically proven: only thermoskin is clinically proven to increase blood flow, increase skin temperature, increase muscle temperature, and minimize perspiration. This provides heat therapy to prevent, treat and rehabilitate soft tissue injuries. Knee sizing guide: measure the circumference just below the knee cap. X-small 11 - 12 1/2 inch. Small 12 1/2 - 13 1/4. Medium 13 1/4 - 14 1/2. Large 14 1/2 - 15 3/4. X-large 15 3/4 - 17. Xx-large 17 - 18 1/4. If in doubt on thermoskin sizing it is generally best to select the larger size.