Vans Knu Stack Platform Shoes. The Knu Stack starts with Vans' modern interpretation of a classic 90s silhouette—and then cranks it up a notch. With double the height, a puffed up tongue, and a 3D-molded Sidestripe, this in-your-face shoe boasts dramatic style details that blend an icon of the past with today’s bold trends. 34mm platform height. Sturdy suede uppers. Puffy tongue and ankle collar. Oversized chunky laces. Heel pulls for ease of entry. Signature rubber waffle outsoles. Imported.