The bottom part of the sole has a textured rubber and in the pictures it looks "dirty" see last photo for closeup of the texture. This vintage Grateful Dead shoe sandal features a unique skeleton sole design, embodying the iconic 90s hippie style. With a size range of 9-11, this original piece is a must-have for fans of the rock & pop genre and the Grateful Dead band. Perfect for collectors of music memorabilia and novelties, this item captures the essence of the era and the band's distinctive aesthetic.