Fresh Foam X midsole foam with approximately 40% bio-based content delivers our most cushioned Fresh Foam experience for incredible comfort. Bio-based content is made from renewable resources to help reduce our carbon footprint. Vibram Eco-Step Natural Outsole provides superior grip and is made by more than 90% petroleum-free ingredients. Vibram is a registered trademark of VIBRAM S.p.A All rights reserved. Micro-Traction Lug by Vibram. Vibram is a registered trademark of VIBRAM S.p.A All rights reserved. Upper features a breathable yet protected construction