The RumbleRoller is a scientifically engineered mobility tool designed to mimic thumb-like, deep tissue massage pressure. This effect helps to break up knotted muscle fibers, decrease muscle tension, and diminish tightness. This roller is much more aggressive than most conventional foam rollers and is able to get deeper in the muscle fascia to reach the toughest trigger points. •Firm but flexible bumps •Closest to mimicking real thumb pressure •Great for all body parts, and works better around bony areas •Recommended for beginners switching over from traditional foam rollers, as well as experienced users