TriggerPointGRIDfoam rollers feature a patented design that offersa superior, multi-density exterior constructed over a rigid, hollow core that withstands repeated use while maintaining shape and integrity. The proven durability of theGRIDhas helped make ita trusted tool of physical therapists, massage therapists, athletic trainers and professional athletes. TheGRIDcan be used to roll through tight muscles, knots and kinks to reduce soreness and improve mobility.Regular use of theGRIDcan provide benefits such as recovery from (or preventing) injuries, decreased muscle and joint pain, increased circulation and flexibility,improved balance and mobility and preparing the body for peak performance.The distinctive, multi-dimensional surfaces of theGRIDreplicate the feeling of a massage therapists hands wide and flat like the palm, long and tubular like the fingers, and small and firm like the finger tips.The textured surface of theGRIDhelps to maximize the flow of blood and oxygen to heal tissue.TriggerPointGRIDfoam rollers are available in three sizes and two densities. Regular density models include the original 13-inchGRID, the 26-inch GRID2.0, and the 4-inch travel-friendlyGRIDMini. The 13-inchGRIDX features extra dense foamfor working the tightest muscles.Purchase of any TriggerPoint GRIDfoam roller includes free access to an online instructional video library from the experts at TriggerPoint that illustrate the best foam roller techniques. 1-year warranty.