Fresh Foam X midsole foam with approximately 3% 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. Structured and breathable engineered mesh upper Reflective accents designed to catch the light Internal gusseted tongue for a secure fit 10 mm drop; due to variances created during the development and manufacturing processes, all references to 10 mm drop are approximate