The Sak Recycled Plastic Fiber Hand Crochet and Smooth Leather Footbed Clogs.Indoor/Outdoor Comfy Stylish Design. Exterior: Hand-crochet, Recycled Polypropylene Yarn • Interior: Cotton Jersey Lining, Leather • Slip-on entry • REPREVE recycled ocean bound crochet string, Leather insole, Padded footbed • Premium leather from a Leather Working Group Gold-Rated certified tannery, REPREVE crochet string made from ocean bound recycled materials including plastics bottles.