Inov-8 Roclite 315 Trail Running Shoes Meta-Flex - this boot incorporates a meta-flex groove which is anatomically aligned in front of the metatarsal heads to provide a natural fore foot flex and protection whilst running. Met Cradle - The upper webbing support in this boot is anatomically positioned to cradle the fore foot behind the metatarsal heads and provide a secure foot hold whilst running. Meta-Shank - New 5 finger meta-shank aligns with each individual metatarsal for greater flexibility when contouring while retaining underfoot impact protection. A softer compound is used on performance product while a firmer compound is used on the endurance product. Fascia Band - This band is a replication of the plantar fascia ligament to increase propulsion efficiency and reduce fatigue in the foot. Mid Level Cushioning - Usually used for training.