From Rothy's, The Merino Wool Washable Casual Clogs feature: Upper is a blend of RWS-certified merino wool and Rothy's signature thread, which is made from recycled plastic bottles V topline construction Slip on styling Unlined Plush, contoured footbed Durable tortoise shell rubber outsole Machine Washable: Toss in the wash. Air dry. Imported. Sizing Notes: Runs big. If you are in between sizes, we recommend sizing down for a better fit.