Altra Superior 4.0
- Altra Quantic midsole balances cushioning and responsiveness while remaining lightweight.
- Inner Flex flex grooves system provides additional flexibility and cuts weight for increased performance.
- Natural Ride System (NRS) design includes a more natural, foot-shaped last, zero millimeter heel to toe drop, and metatarsal-specific shapes in the outsole to assist in proper foot mechanics and allow for more natural foot movement.
- Natural Foot Design follows the natural shape of the foot for ultimate comfort.
- Removable StoneGuard Rock Protection slips underneath the sockliner to disperse shock and protect the feet from rock-bruising. StoneGuard weighs 1.0 oz and is 1 mm thick (Men's size 9).
- Trail Claw outsole design uses a sticky rubber multi-directional pattern, combined with updated lugs under the forefoot and claws under the toes to provide improved grip and stability on trails.
- FootPod outsole design follows the natural construction of the human foot for maximum flexibility and a responsive ride.
- MaxTrac Outsole uses anatomically-shaped sticky rubber that prioritizes grip and durability on uneven terrain.
- Quick Dry Air Mesh is updated for durability, wicking water away from your foot while remaining light and breathable.
- Seamless Upper reduces irritation and provides next-to-foot comfort.
- Gaiter Trap is a velcro strap that secures trail running gaiters to the shoe, preventing debris from building up beneath the shoe (matching gaiter sold separately).
- Synthetic Overlays provide long-lasting support.