The adidas UltraBoost 21 'Black Iridescent' offers both an impressive performance and a commitment to sustainability. Incorporating Parley Ocean Plastic, the black Primeknit upper is not only durable but also environmentally friendly. To enhance its structure, the sneaker features a transparent TPU material on the external heel counter and midfoot cage, with the latter showcasing a captivating iridescent bronze finish on its three-stripe branding. Delivering an incredibly responsive ride, the shoe's full-length Boost midsole contains an increased number of Boost capsules compared to its predecessor. Furthermore, the Continental Rubber outsole ensures optimal traction, making it perfect for various terrains.