SWiG 50oz travel bottle-ocean - why should you choose SWiG? superior temperature retention (hot/cold) - swig's double-wall Vacuum insulated tumblers will keep your drinks seriously cold (or hot!). swigs are engineered to maintain the temperature of your beverage for the maximum time possible with current technology. Vacuum insulation - SWiG premium drinkware uses double-wall vacuum-sealed insulation technology, which means the space between the stainless steel walls is void of matter. With no medium for heat to transfer, your Drink's temperature will not be impacted by the outside temperature. 304 grade - 18/8 stainless steel - crafted from 304 grade 18/8 stainless steel. All drinkware is BPA free, FDA approved, highly resistant to rust, absorbing odor, retaining taste and bacteria, and easy to clean by hand. Clear lids and stainless steel caps - the 9oz wine, and 20oz and 30oz tumblers all have a clear push-seal lid while the 17oz and 50oz bottles have a stainless steel twist-off cap. Both closures feature a rubber seal gasket for better temperature control and are dishwasher safe. Copper coated inner walls - swig's double-wall stainless steel inner walls are copper plated, which provides an additional barrier against heat entering or exiting the vessel. Sweat free - swig's double-wall Vacuum insulation prevents condensation from ever forming on the exterior. Hot liquids will not impact the exterior, either. This means SWiG will always be comfortable to hold and never make a watery mess in your hand or on your table.