Brooks Women's Trance 9 Running Shoe 100% Mesh and synthetic Rubber sole Full Length BioMoGo provides a more cushy first feel that lasts and is enviornmentally friendly Rearfoot and Forefoot Hydroflow enhance midsole cushioning Full-length S-257 Cushsole gives the runner even more cushion with each stride Progressive Diagonal Rollbar (PDRB) is biomechanically engineered to allow for progressive pronation control and creating a smoother transition from heel to toe DRB Accel provides torsional rigidity to midfoot, enhancing support