Composed of hard, dense materials, the TriggerPoint GRID X 1.0 Foam Roller - 13" - Black digs deep into tight muscles to relieve aches and pains. Ideal for use on larger muscle groups like the calves, quadriceps, hamstrings, back, and lats. The GRID X is not recommended for beginner rollers. 1-year manufacturer's warranty. TriggerPoint empowers people of all lifestyles to move and feel better. TriggerPoint designs and develops innovative massage therapy tools that mimic the touch of a therapist's hands - making their foam rollers, hand rollers, massage sticks and balls ideal for individuals of all ages, sizes, and athletic ability. Features: Twice as firm as the original GRID® Foam Roller Sweat-proof and easy-to-clean material 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 Superior construction won't break with repeated use Weight tested to support up to 550 lb. (250kg) static load Backed by 1 year warranty