From day one of training to the finish line, you can rely on the do-it-all performance of The One from Altra Zero Drop. Altra Zero Drop recommends that those new to natural running and zero-drop footwear transition slowly by wearing these on shorter runs and gradually building up to regular mileage. A natural running shoe with a zero-drop differential that is designed for the neutral runner looking for a barefoot-inspired feel without sacrificing cushioning. Ideal for running, road racing and speed work. Lightweight, quick-drying air mesh upper. Contoured heel cup for added comfort. Includes 5 mm Contour insole for light underfoot cushioning. Dual-layer midsole is made up of EVA and A-Bound material. Zero Drop Platform promotes a more natural foot strike and a more efficient stride. Total Stack Height (total thickness of the shoe): 18 mm. FootPod delivers optimal flex, responsiveness and traction. Foot-shaped design allows the foot to splay naturally and helps maintain proper alignment, while maximizing shock absorption and promoting a more powerful toe-off. Imported. Measurements: ; Weight: 7 oz ; Product measurements were taken using size 9, width B - Medium. Please note that measurements may vary by size.