Polar Camel 30 oz. Black Ringneck Vacuum Insulated Tumbler w/Clear Lid.��30 oz. Stainless Steel Polar Camel Tumblers features double-wall vacuum insulation with a clear lid. The mug has a narrower bottom to fit most standard cup holders. It is 2X heat & cold resistant compared to a normal tumblers and is BPA and lead free. Polar Camels are made from 18/8 gauge stainless steel (18% chromium/8% nickel) - also known as Type 304 Food Grade.