TriggerPoint GRID Foam Roller with Free Online Instructional Videos, X Extra Firm (13-inch) NA Imported Patented foam roller design offers a superior, multi-density exterior constructed over a rigid, hollow core Constructed from quality materials that won't break down or lose shape from repeated use Includes access to free online instructional video library on foam rolling best practices from the experts at TriggerPoint Trusted foam roller of physical and massage therapists, coaches, trainers and athletes provides muscle recovery, pain relief and improved flexibility GRID X: Extra-firm density, 13 x 5.5 inches; 550 pound weight limit; 1 year manufacturer's warranty