The GoFit Extreme Massage Roller's patent-pending Egg Crate design performs like an aggressive sports massage for tired and sore muscles. The Egg Crate design's firm-molded "Peaks" aggressively pinpoint and break up sore, knotted muscles or trigger points. Simultaneously, the Peaks and Valleys roll smoothly over muscle curves and harder body parts without causing discomfort. This self-massaging process relaxes muscle tissue also promoting more flexible movement. So, manage your muscle pain for maximum relief with GoFit's Extreme Massage Roller. Patent Pending, Egg crate design provides deep tissue massage, pulverizing trigger point areas for maximum relief. 4" Rigid hollow core design stands up to heavy use and allows user to grip roll ends for greater control and added core-strengthening exercise options. Dense, closed-cell foam offers durable firmness with soft-touch surface.