Ideal for use immediately following physical activity; roll upper and lower body including calves, adductors, quadriceps, hamstrings, and upper backVibrating foam roller with opposing ridge curves, and three vibration frequencies to ease muscle pain and discomfort, and accelerate recoveryRythmic squeeze and stretch motion provided by the CHARGE pattern, in combination with vibration technology, comfortably releases muscle tensionOpposing high and wide ridges stretch the muscle, while high and narrow ridges squeeze the muscle to increase circulation to hard-to-reach muscle tissuePortable at 7 x 4 inches, weighs 2 pounds; rechargeable battery lasts up to 2 hours; AC charger included; manufacturers one-year limited warranty