Kalahari | Waterproof | Birko-Flor | Futura Black"The BIRKENSTOCK Kalahari for women designed to bring Birkenstock comfort and support to your favorite trail and water based activities. These off road ready sandals feature a direct attach PU footbed, a rugged PU TPU outsole for added traction and sturdy hook and loop closures for a secure fit. The upper is made from the skin friendly, hard wearing synthetic material Birko Flor." BIRKENSTOCK US Anatomically shaped PU footbed Upper: Birko Flor Futura