Three pairs of heads come with this personal massager for a choice of soft, medium, or hard percussion massage. The heads are 1-3/4-inch-diameter domes that twist on and off the heavy (about 3 pounds) power unit and pulse at 3,100 times per minute to send penetrating massage action deep into muscles. A variable-speed control offers options ranging from gentle to vigorous. To fit various body areas, the spacing between the heads can be adjusted through a range of 2-1/2 to 3-1/2 inches at the push of a button. The massager has a soft, ergonomic handle for a secure, comfortable grip and measures 13 inches long. That length ensures all body areas can be reached, and the 12-foot power cord permits the massager to be used a long way from a wall socket. The massager carries a two-year warranty against defects. Model Number: PA-100 Instruction Manual 2-year warranty