Therapeutic moist heat for soothing warmth and pain relief. Filled with unique microbeads that absorb and retain moisture. Once heated, they slowly release the moisture for deep, penetrating heat. Soft fabric is comfortable against the skin. Ideal for arthritis, back or muscle aches and stiffness, neck pain, sprains, strains and sports injuries. Heats easily in the microwave, reusable. Oval size (9"" X 12"") works great for the neck, lower back, shoulder or leg.