Simple Modern Wave Water Bottle - Vacuum Insulated Double Wall 18/8 Stainless Steel Vacuum Insulated: The Simple Modern Wave water bottle is double walled and vacuum insulated, which keeps your favorite beverage hot or cold for hours 18/8 Stainless Steel: Bottle is made from premium gauge 18/8 stainless steel Premium Copper Coated Insulation Layer: The exterior of the inner wall, in the vacuum sealed area, is coated in a thin layer of copper for added insulation Take it With You: narrow mouth reduces spills and sloshing while you drink; 9oz and 17oz sizes fit in most cupholders, the 25oz and 34oz bottles are too big Why Simple Modern: Our core principles of Generosity and Excellence have inspired us to sell high quality products, act as great partners with everyone we interact with, and give away a minimum of 10% of our profits Keeps liquid cold for 18 hours, hot for 5 hours. Fits in cupholders. Perfect for Kids. Keeps liquid cold for 24 hours, hot for 10 hours. Fits in cupholders. Keeps liquid cold for 28 hours, hot for 12 hours. Does not fit in cupholders. Fits a full bottle of wine. Keeps liquid cold for 36 hours, hot for 14 hours. Does not fit in cupholders.