With a seamless, irritation-free fit and customizable Pump Air Cage, the Reebok ZPump Fusion 2.0 is ready to change the running game. Seamless PowerFrame Fusion Sleeve upper. Pump Air Cage creates an adaptable, custom fit for every runner, every time. Molded 5mm sockliner adds extra cushioning underfoot. Foam midsole with reinforced midfoot platform for lightweight cushioning and a strong foundation. CRTek high-abrasion rubber in high-wear areas of the outsole for durable traction where you need it most.