The Mizuno Wave Sonic Performance Running Shoe is a low-profile training and racing shoe with a sleek, glove like-fit. It has U4icX foam Wave technology and increased toe spring for a lightweight, fast feel and a lower midsole drop for natural running position and efficiency. Runner Type: Neutral Drop: 4mm Midfoot U4icX Wave construction for lightweight cushioning. Lower midsole drop for natural running position and efficiency. Increased toe-spring midsole and zig zag shaped outsole for quicker