New Balance Women's WR8509 Running Shoe 100% Mesh and synthetic NB ZIP is strategically located struts engineered between top and bottom plates, formulated for optimal cushioning, responsiveness and durability ABZORB SBS is an engineered, non-cellular elastomer designed to provide optimal shock absorption and no compression set C-CAP is a compression-molded EVA for superior midsole cushioning and flexibility Ndurance is a rubber compound for maximum durability used in high wear areas ABZORB provides a superior blend of cushioning and compression set features with Dupont Engage and Isoprene rubber for the ultimate ride