PRICES MAY VARY. Upper: Upper is made of ultra-light stretchy mesh, which allows them to flex with feet to fit more uniformly. Breathable air hole on the mesh upper allow air to flow through swiftly to provide cross ventilation. Outsole: Non-slip rubber outsole with texture grooves on the bottom to provide superior traction available for those times when you are navigating fast-moving whitewater or rocky beaches. Insole: Cushioned insole with breathable honeycomb design provides maximum comfort