Functions: - The 360 cap is leak-proof and couldn't be easier to use: press the center button, sip from either side, then press again to close. It is made of BPA-free plastic with a seal. - Thermo 3D™ double-wall vacuum insulation technology maintains the beverage temperature - hot or cold. - The walls are made of 18/8 medical grade stainless steel. The outer wall is Hardshell™ powder coated. The substance does not transfer taste and does not add a metallic aftertaste. - Hand washing is recommended, but the mug can be washed in the dishwasher on the top rack. - Each item is marked with a code at the bottom. You can register the code on the website and track the environmental project you supported with your purchase! - Packed in a cardboard box.