S'well Bottles are made of double-walled, insulated 18/8 highest grade stainless steel to keep beverages hot for 12 hours and cold for 24 hours, without any condensation on the outside, ever. Ice stays in your bottle and steam stays trapped with the cap that prevents leakage, and holds carbonation. In order to achieve constant temperature maintenance, they created a new advancement in metals science called ThermaS'well Technology. This sexy bottle has a top big enough to fit ice cubes and a slim profile that fits perfectly in a standard-sized cup holder or in your bag. As if that's not enough, S'well also proudly supports the U.S. Fund for UNICEF, donating $100,000 to help bring clean water to the world's most vulnerable children. They also support American Forests and Drink Up. It's the only reusable bottle that looks great and do good.