Mizuno Running - Wave Revolver 2 (White/Black/Orange) - Women's: Engineered for the racer with a flexible foot-type who need the comfort of a racing shoe and the protection of a training shoe in a lightweight package. 18mm/9mm (heel to forefoot ratio). The pebax wave plate allows for cushioning in a lightweight racing shoe. X-10(tm) in the heel for durability. Blown rubber in the forefoot for cushioning and flexibility. Shoe weighs 7.1 ounces.