For Muscles & Joints. Multipurpose Relief for Pain & Stiffness. Odor Free. Lasts up to 8 Hours. 4 large pads 3 3/4" x 5". WellPatch Heat Warming Pad is a safe, odorless warming therapy that provides hours of soothing relief from minor aches, pains, and stiffness of muscles and joints. This comfortable heating pad applies directly to the skin and can be worn unnoticed under clothing as you go about your daily routine. Product is Air-Activated Do not open until ready to use. Open pouch to activate warming pad. Remove protective film. Apply pad directly to area of discomfort, adhesive side towards skin, or toward clothing for delicate or aging skin. For best contact with skin, apply to dry, flat area, free of moisture, oils or lotions. To remove - slowly peel off the pad. Pad will not re-stick well once removed. Storage and handling. Avoid exposure to direct sunlight or heat. Store in a dry place.