Individuals with pacemakers and pregnant women should consult their doctor before using this product. Circular thumb action massage mechanism helps relieve muscle fatigue, with soothing heat to help ease stiffness and tension. Moving massage moves up and down the back. 3 massage zone settings: full, upper and lower back. Durable and comfortable fabric cover. Fits most chairs for easy use in home or office. Adaptor. Manufacturer's 2 year guarantee.