Birkenstock Kaprun Rivet Doubleface Wool Clogs. Product Details Color: Rare Fuchsia/Orange. Material: The upper is made of wool felt, and the interior is lined with genuine shearling for warmth. Features: Anatomically shaped cork-latex footbed for support. Signature Birkenstock rivet detail on the side. Doubleface construction, where the outer felt and inner wool are part of the same material. There are some spots on the toe of the right shoe, as seen in pics. Not noticeable but want to be transparent.