From the manufacturer's website:
Dry Heating Pad with Select Heat Switch is recommended for use whenever heat therapy applications are desirable for personal comfort, or as recommended by your physician for the relief of pain. 60 minute auto-off Select Heat Switch with ON indicator light. 4 automatically controlled heat settings. Wet proof pad construction. Removable, hand washable, cloth cover. Sponge pad for moist heat.
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.