The adidas Ultra Boost 4.0 Grey is a running shoe by adidas made with high-performance technology. The adidas Ultra Boost 4.0 is available in a grey and Core black colorway. The shoe’s upper is made from a stretchy textured Primeknit that gives it a sock-like fit. This makes the shoe lightweight and allows the shoe to adapt to the shape of your foot as you move. The sneaker has a responsive Boost midsole cushioning, a flexible outsole made from continental rubber, a midfoot cage, and a supportive heel counter. The adidas Ultra Boost 4.0 Grey was released on 2nd December 2018 with its retail price set at $180.