- Fresh Foam X midsole with approximately 3% bio-based materials delivers our ultimate Fresh Foam experience for incredible comfort. Bio-based materials are sourced from renewable resources to help reduce our carbon footprint - Synthetic/mesh construction - Toe Protect technology protects against rocks, roots and debris - Two-piece midsole provides added durability - Adjustable lace closure for a custom fit - 4mm drop; due to development and manufacturing variability, all references to 4mm drop are approximate. - MTMORNB1