Stainless Steel, Double Wall Vacuum Insulated, Powder Coated, Durable No Sweat Design, Cup Holder Friendly, 304 Stainless Steel (18/8 Food Grade) and BPA Free. Keeps your beverages cold up to 12 hours and hot up to 6 hours. The handle is welded to tumbler so there's no need to worry about handles not fitting properly. Dishwasher safe, but hand wash to preserve imprint. Please do not put in microwave oven or refrigerator and allow very hot beverages to cool down 2 - 3 minutes before placing lid on tumbler.