The adidas Ultra Boost 21 Parley Carbon is a long-distance running shoe built with Ultra Boost technology as a collaboration between the two brands. This iteration features an upper made with a mix of lightweight and breathable materials. The upper is mostly black, with a shiny black mudguard that features light blue stitching. Light blue forms the heel counter, branded with the Ultra Boost name. The shoe features black laces along with Sandy Beige secondary laces secured to the sides. A heel pull tab in Sandy Beige complements the design. The tongue showcases a branded adidas and Parley logo patch, while another black tab with both companies’ branding appears on the heel. It sits atop a textured white sole with Ultra Boost technology. What we like best is the secondary lacing system, adding a pop of color and unique design. Additionally, the Parley x adidas UltraBoost 21 'Carbon Sandy Beige' dresses the performance running shoe in earth-friendly materials. The black Primeknit upper is composed of 50% recycled polyester and 50% Parley Ocean Plastic, featuring upcycled plastic waste gathered from coastal communities. The sock-like build is supported by tonal no-sew overlays and a teal-colored TPU heel counter. Responsive cushioning arrives via a full-length Boost midsole, reinforced underfoot by a grippy Continental Rubber outsole.