Adidas Ultra Boost X Yeezy Boost Running Shoes are combined with the benefits with Ultra Boost Shoes and Yeezy Boost Shoes. These shoes feature a breathable Primeknit upper for a flexible and supportive fit. With a STRETCHWEB outsole that enhances the energy returning properties of boost?. Boost?'s energy-returning properties keep every step charged with an endless supply of light, fast energy.