This massager combines heat, infrared heat therapy, magnetic therapy, plus acupressure massage to stimulate circulation and help soothe joint pain. This can also help muscle stiffness in knees, shoulders, and elbows. Four infrared lights along with six tungsten warming lights stimulate circulation and deliver deep, penetrating thermal energy to tissue and joints. A timer automatically shuts off after 30 minutes - the recommended time for infrared heat therapy. The independently controlled vibration provides a soothing massage. The massager has a padded body, fits knees with a girth of up to 20", and includes an AC adapter, adjustable straps for use on knees and elbows, and one adjustable strap for shoulders. 10" x 9" x 3".