The Yzy Bst 350 "Mono Clay" is one of three colorways that debuted a new construction of the silhouette in June 2021. The "Mono" series, which includes this "Clay" colorway along with "Mist" and "Ice" versions, features a departure from the model's usual Primeknit woven upper, instead opting for a translucent monofilament mesh material. Below the mesh exterior is a supportive "web" design. The "Mono Clay" colorway features an earthy shade of reddish-orange across the upper, much like the initial "Clay" Yzy 350 from 2019. The monotone Clay theme continues on the heel pull tab, laces, and translucent rubber sole. The "Mono Clay" Yzy 350 released exclusively in Asia, while the "Mono Ice" and "Mono Mist" colorways released in North Ameria and Europe, respectively.