FuelCell midsole foam with approximately 3% bio-based content delivers a propulsive feel to help drive you forward. Bio-based content is made from renewable resources to help reduce our carbon footprint,Lightweight textile upper with Ariaprene synthetic foam fabric tongue and gore,Bootie upper construction hugs your foot for a snug, supportive fit,Upper features no-sew overlays for a sleek fit and feel,Lightweight EVA foam cushioning in the midsole and heel increases comfort