Zappos.com is proud to offer the Mizuno Running - Wave Phantom 4 (White/Navy/Red) - Women's: Engineered for the racer who needs the best blend of support and cushioning due to the flexible foot-type of this racer. 22mm/11mm (heel to forefoot ratio). Fan-shaped Wave provides an optimal blend of support and cushioning in a lightweight racing shoe. Outsole: X-10 in the heel for durability; blown rubber in the forefoot for cushioning and flexibility. Shoe weighs 8.1oz.