Sanuk Highland Sling ST - Women's Shoes : Black : The primary materials that compose this product contain a minimum of 20 percent recycled content. Make a stylish statement with every step you take wearing Sanuk Highland Sling ST Sandals. Cotton, repreve our ocean recycled polyester, two-way stretch knit, jersey, synthetic upper. Synthetic lining. High rebound soft top foam footbed featuring bloom foam made with repurposed algae. Open round toe. Slingback closure.