The adidas Ultra Boost 21 Grey White arrives in an all-grey body with a tech-knit finish sitting on a white sole adorned by a textured pattern. adidas uses its PRIMEKNIT technology on the Ultra Boost 21. Thus, the shoe’s upper features a recycled PRIMEBLUE material in crisp white knit. The solid weave finish of the mudguard breaks into a breathable surface on the vamp. The 3-Stripes of adidas, which join on the eye stay to make an overlay, appear in a synthetic material on the quarter panels. The heel stabilizer is in plastic and it curves near the counter to make a "U" shape. What makes the adidas Ultra Boost 21 Grey White stand out? Our experts have a soft spot for the sock fit of this shoe. While the breathable knit design ensures comfort, the grey lace closure ushers in a secure fit. When it was released on January 28th, 2021, this shoe had a retail price of $180.