Great for soothing arthritis pain, backaches and muscular aches. The TheraBeads in this pack provide moist heat therapy recommended by doctors for its deep penetrating qualities. The beads in all TheraBeads products have a patented coating that captures moisture from the air, and the beads rejuvenate themselves when not in use. Once heated in the microwave, the TheraBeads release their retained moisture. Just give this pack 30 seconds in the microwave and let the soothing begin. Microwave instructions included.