The adidas Ultra Boost 4.0 Grey is a running shoe by adidas made with high-performance technology. It features a stretchy textured Primeknit upper that gives it a sock-like fit, making it lightweight and adaptable to the shape of your foot as you move. The sneaker includes responsive Boost midsole cushioning, a flexible outsole made from continental rubber, a midfoot cage, and a supportive heel counter. Released on December 2, 2018, this shoe offers both style and functionality with its minimal grey and Core black colorway.