The adidas Ultra Boost 21 Solar Yellow takes the Ultra Boost 21 silhouette and applies a vibrant colorway of Solar Yellow with Screaming Pink details. The upper is made of breathable PrimeKnit that conforms to the foot's shape and adds durability. However, part of this PrimeKnit is made of PrimeBlue thread, which is made from recycled materials, including plastics found in the oceans. The laces wind through overlays made of a synthetic material that forms the 3-Stripes logo. The sneaker boasts a Boost midsole, as well as adidas’ Torsion System, which increases energy return. Finally, a heel counter supports the heel, while the outsole is made of rubber. The branding details are minimal, but include a panel near the heel that reads 'ULTRABOOST.' Something our experts at StockX like is the Screaming Pink accents on the midsole and outsole. The adidas Ultra Boost 21 Solar Yellow was released on January 28th, 2021, and sold at $180.