Mizuno Running - Wave Mercury 4 (White/Brick/Navy) - Men's: Developed for the runner who desires the best blend of stability and cushioning in a package that respects the needs of the medium arched, flexible foot-type for whom it is intended. 24mm/12mm (heel to forefoot ratio). Composite Double Wave provides a great blend of stability and cushioning for the runner that needs structured stability due to a foot-type that is medium-arched and moderately flexible. The Composite Double Wave is made of pebax and graphite to give specific cushioning at heel strike (pebax) and prevent overpronation medially (graphite) in the heel to midfoot phase of the gait cycle. X-10 in the heel for durability. X-10 provides the most durable carbon rubber from Mizuno that allows for longer wear in high impact areas and provides more traction at heel strike. Solid rubber in the forefoot for durability and flexibility. Shoe weighs 11.5 oz.