ASICS Women's GEL-Cumulus 11 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 Gender Specific Space Trusstic System recognizes the normal periodic changes in the shape of the woman's arch and provides for the controlled deformation of the arch into the space within the system Twist Gel Cushioning System enhances shock attenuation and allows for improved toe-off position