10" ACUPRESSURE WHEEL: Applies even, pinpoint pressure to the muscles surrounding your spine to loosen knots and improve blood flow Unique massaging bumps that envelope the tissue around your spine resulting in satisfying spinal traction (stretch) and myofascial release (massaging the muscle tissue) It is every bit as effective as the original Chirp Wheel while adding the benefits of having a masseuse in your home WARRANTY & DETAILS: Includes a 10 year manufacturer warranty against defects Each wheel can support up to 500 lbs.