ASICS Women's GEL-Evolution 5 Running Shoe 100% Synthetic and mesh Rubber sole Impact Guidance System (I.G.S.) enhances the foot's natural gait from heel strike to toe-off Solyte midsole material is lighter than ASICS' standard EVA and SpEVA, combined with improved cushioning and durability Space Trusstic System creates a pocket between the Trusstic System device and the midsole, allowing for greater midsole deformation and more efficient foot function DuoMax Support System ensures that the shoe maintains proper support for the foot during the critical transition from heel strike to toe-off Biomorphic fit upper provides a superior fit and function