Can be used in either the knee or wrist elasticated wrapup to 8 hours warming relief ready to use and non medicinalportable cura heat arthritis refill packs are air activated heat packs designed for use in either the knee or wrist elasticated wrap of the cura heat arthritis pain products once inserted into either the knee or wrist elasticated wrap they deliver deep comforting heat for up to 8 hours and provide targeted temporary relief to arthritis pain with no need for prepara