Vacuum Insulated: The Simple Modern Ascent water bottle is double wall and vacuum insulated. This technology keeps your beverage hot or cold for hours. Specific details for each size are listed in the description and the featured photos. No need for koozies or coasters! No matter the temperature of the liquid in this bottle, it will never sweat or be hot to the touch. 18/8 Stainless Steel: This reusable bottle is made from premium gage 18/8 stainless steel. This material is BPA free and will never rust or leave a bad metal taste in your mouth. This product is not dishwasher safe but the wide mouth makes it easy to clean. Insulated Handle Lid: The lid that comes on the Ascent bottles has a handle, for comfortable carrying. The lid is double walled, adding more insulation to your beverage and preventing condensation. Internal threading on the narrow mouth Ascent lid makes for a more sleek bottle and more comfortable drinking. Premium Copper Coated Insulation: The exterior of the inner wall, in the vacuum sealed area, has been dipped in copper for added insulation. Copper reduces the transfer of temperature, adding even more insulation to your bottle. Narrow Mouth Opening: The Ascent bottle has a narrow mouth opening, reducing spills and sloshing when drinking. The narrow opening increases the temperature retention qualities of the vessel. Ice fits through the opening, one at a time.