The Grid, by Trigger Point Performance, is a versatile and comprehensive foam roller, with unique Distrodensity Zones, a matrix of varying widths and densities that allows for a precision massage based on individual needs. Just as a massage therapist uses different parts of the hand and arm to manipulate different muscle groups, The Grid"s Distrodensity Foam Zones enable you to apply varying amounts of pressure to massage and release tight muscles. At 13 inches long by five inches diameter, the compact Grid is highly portable and yet still able to support up to 500 pounds. The Grid is designed for athletes and people of all types and skill levels, from distance runners to professional athletes to yoga enthusiasts to those simply seeking to keep active. It"s an ideal tool for massaging lats, quads, lower back, or any other large muscle group, or achieving a challenging core body workout.