Flexible ESS rock plate protects against stone bruising caused by sharp rocks and roots; Anatomical toe box allows toes to spread naturally and comfortably; Vibram Outsole offers onparalleled grip and traction and durability from the leaders in technical outsoles; Gaiter Compatible - Offers additional protection from dirt, rocks, and twigs on the trails (sold separately); Best for Trail Running; Stack Height: 25mm (heel) / 22mm (forefoot); Heel to Toe Drop: 3mm; Weight: 10.1 oz (M9)