Polar Camel 20 oz. Ringneck Vacuum Insulated Tumbler w/Clear Lid The primary feature in Polar Camel Tumblers is the double walled, vacuum sealed insulation method, which provides double the insulating power of most tumblers, and also keeps it sweat-free on the outside. This tumbler keeps drinks hot up to 6 hours and keeps iced drinks cold for more than 24 hours. The Polar Camel logo is on the top of the clear lid with a hole big enough to hold a straw. The stainless steel construction means the polar camel cups are BPA and lead-free. The narrow design of the base of most sizes allows the tumbler to be used in standard drink holders.  The seamless construction prevents any leaks from the body of the tumbler. You can put boiling water in the tumbler, but it is not recommended that you wash with a dishwasher. Stick to handwashing to preserve the quality of the cup. Polar Camels are made from 18/8 gauge stainless steel (18% chromium/8% nickel) - also known as Type 304 Food Grade.