Our travel tumbler is made with 100% double wall, copper-insulated technology keeping your drinks cold for 12+ hours and hot for 6 hours. These travel tumblers are made from premium 304 food-grade stainless steel which will never rust and is lead-free. The snap-on lid comes with a rubber gasket that forms a tight vacuum seal for maximum spill-proof capability and features a sliding spill-resistant top for simple one-handed operation. There is a wide mouth drinking hole on the top, with space for a straw as well. Our travel tumbler is so lightweight you can easily carry it anywhere and its slim design fits most automobile cupholders.