100% Oystex Polyester, 275gsm. Made with Oystex technology, The Oyster Shell combines oyster shells and recycled polyester in this ultra-durable ripstop fabric. The Features waterproof welded zippers, velcro cus, elastic drawcords with embedded clasps at hood and waist. The special welded membrane and DWR coating combines to achieve a 10,000mm waterproof rating. It’ll keep you dry in the wettest of conditions.