The Trigger Point Universal Double Massage Ball 8-Inch Textured Roller is ergonomically-designed, in the shape of a peanut, to target hard-to-reach muscles all throughout the body. It is ideal for large muscles such as the glutes, hamstrings, and quads, and the unique, double-ball design allows for massage up and down the spinal column without uncomfortable pressure on the spine. The textured surface pattern increases mobility and aids in recovery after workouts. For use on the entire body, its unique shape is especially suited to the neck and back, for relieving tension, releasing tightness, and soothing pain. The Trigger Point Universal Roller is a compact and portable 8-inches long, and easily fits in a gym or work bag for travel-friendly massage. The EVA foam construction won't break down or lose shape after repeated use. Roller measures 8 x 5 inches and weighs 0. 90 pounds. Water-resistant and easy to clean. Manufacturer one-year warranty.