Dense tissue needs a firmer GRID foam roller to release and relieve aches and pains. The GRID X can be used to release the calves, quadriceps, hamstrings, back and lats. The GRID X foam roller is our firmest foam roller. It was created to break through the body's toughest, tightest trouble spots for relief from intense aches and pains. The GRID X foam roller is designed with proprietary Distrodensity zones. This three dimensional surface has a variety of widths to replicate the feeling of a massage therapist’s hands: Low and Flat - Feels like the palm of the hand or forearm High and Firm - Feels like the finger tips Medium and Tubular - Feels like the fingers and thumb Designed for all types of athletes from Crossfitters to footballers to yoga enthusiasts, The Grid X foam roller is as versatile as it is fashionable. Product Specifications: Twice as firm as the original GRID foam roller Sweat proof and simple to clean Three-dimensional surface allows tissue to aerate while you roll, promoting the flow of blood and oxygen—the nutrients needed to repair muscle Compact and travel-friendly Backed by a one-year warranty Weight tested to support up to 550 lbs/250 kg static load Perfect for dense tissue and anyone who prefers intense compression.