Offering the perfect balance of cushion with a zero-drop, Altra Instinct 3.5 running shoes. Your feet would thank you if they could for slipping them into this flexible and relaxed design. Neutral runners will love the spring they add to every step.Upper: Quick-Dry mesh provides breathable flexibility. Flat laces reduce irritation. Padded tongue and heel collar enhance comfort. Midsole: INNERFLEX™ grid-like flex grooves in the midsole allow the foot to flex where it needs to for more speed and better performance. FootShape™ allows the toes to relax and spread out naturally and the big toe to remain in a straight position for more speed and stability. Zero Drop™ places the heel and forefoot the same distance from the ground to encourage proper, low-impact form. Abound energy-return compound sits directly under the foot to reduce gound impact and add a spring to each step.Outsole: Foot Pod Technology™ unique outsole and midsole pattern maps the bones and tendons of the foot to let it flex where it naturally wants.