Aircast Cryo/Cuff Knee is a cold therapy cast for relieving pain and swelling in the knee. Can be used for multiple knee injuries, such as knee ligament sprains, cartilage tears, and ACL injuries; and following knee arthroscopy and knee surgery. Size M. For checking the right size, measure around the upper leg, 15 cm above the knee cap. Large = 50-80 cm, Medium = 45-60 cm. Aircast Cryo/Cuff Cooler is required and can be purchased seperately.