Twice as firm as the original GRID foam rollerIt was created to break through the body's toughest, tightest trouble spots for relief from intense aches and painsDense 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 latsSweat proof and simple to cleanThree-dimensional surface allows tissue to aerate while you roll, promoting the flow of blood and oxygen—the nutrients needed to repair muscleCompact and travel-friendlyWeight tested to support up to 550 lbs/250 kg static loadPerfect for dense tissue and anyone who prefers intense compression