Inspired by the needs of class V river guides. The PFD Sandal(TM) combines the secure and adjustable fit of Astral&&';;s award-winning life jackets with the Balanced Geometry(TM) and legendary G Rubber(TM) grip of our world renowned Loyak(TM) water shoes. A purpose-built Thwart Pad provides comfort while wedging under raft thwarts, and allows the PFD Sandal(TM) to be cinched tight to run, jump, swim and climb in and around the river. Technical Details:- Intended Use: Water, Casual, Boat, Travel Uppers: 100% recycled polyester canvas Midsole: 75C closed cell EVA foam (13 mm thick) Outsole: Flex Grip(TM) outsole with G.ss Rubber(TM) Foot to Ground Distance: 16mm Weight/shoe: M9 = 8 oz (227 g) Sizes: Men&';s US 8-14 (whole sizes only) Fit: True to size (for half size, size up)