22 oz. Stainless Steel Polar Camel Tumblers feature double-wall, vacuum insulation with a clear lid. They are 2X heat and cold resistant compared to glass or plastic bottles. Polar Camels are made from 18/8 gauge stainless steel (18% chromium/8% nickel) - also know as Type 304 Food Grade. Not recommended for dishwashers, hand wash only.