With the Altra Superior 3.0, the Zero Drop running creator takes their much loved trail shoe and added a few updates. This edition features a much stronger upper to withstand the demands of running on aggressive terrain. The slightly flared outsole on the lateral side offers much needed stability for speedy and agile trail running. Runners will continue to feel the benefits of the TrailClaw™ outsole and the GaiterTrap™ technology to ensure optimal performance on even the toughest trails. Upper: Padded tongue and heel collar enhance comfort. Flat laces reduce irritation. Quick-Dry Trail Mesh offers breathable flexibility. Minimal Seams provides enhanced comfort. Gaiter Trap located on the heel. Midsole: Zero Drop™ Platform places your heel and forefoot the same distance from the ground to encourage proper low-impact form. EVA midsole with A-Bound™ recycled energy-return compound sits directly under the foot to reduce the impact of hard surfaces and add a spring to each step. InnerFlex™ grid-like flex grooves in the midsole allow the foot to flex where it needs for more speed and better performance. Outsole: StoneGuard™ offers flexible protection from the rugged terrain by deflecting rocks into the midsole for a smooth, stable ride. Sticky rubber outsole with Trail Claw™ positions canted lugs directly below the foot metatarsals and cl aws near the front of the shoe for incredible traction in any trail condition.