ASICS Women's GEL-Kayano 16 Running Shoe 100% Synthetic and mesh Rubber sole Impact Guidance System employs linked componentry that enhances the foot's natural gait from heel strike to toe-off Guidance Line is a vertical flex groove that decouples the tooling along the line of progression for enhanced gait efficiency, and Plus 3 technology offers 3mm of additional height on women's models to help relieve achilles tension Gender Specific Forefoot Cushioning provides a cushioned platform feel in the forefoot, and women's models help relieve Achilles tension 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 Asymmetrical lacing design reduces potential for irritation and provides improved comfort and fit