KEEN Men's Zambezi Raven/Gargoyle Sandal Synthetic Rubber sole Open TPU-reinforced upper - Key placed panels from heel to toe for optimal ventilation and abrasion resistance for long-lasting use. One-pull adjustable strap system - A single pull for a secure, dialed fit. Textured EVA footbed - Cradles your feet in all-day comfort with its anatomical arch support. PU midsole - A durable damping foam that helps reduce pressure pushed on the underfoot with bounce back properties. Textile-reinforced rubber sole - Sure-footed grip over slippery surfaces.