18 ounce wide mouth vacuum insulated water bottles are the ideal size for the active person. Its 18 ounce capacity and compact size makes it very easy to throw it into your gym bag, backpack, and more for keeping hot or cold beverages with you all day. The double-wall vacuum insulated bottle is specifically designed to keep liquids hot or cold all day. Double-wall technology also prevents condensation and keeps the outside wall of the bottle at a comfortable temperature, regardless of whether it is carrying a hot or cold beverage. These bottles are constructed from high quality, food grade 18/8 stainless steel, which unlike aluminum bottles, does not require any kind of liner. The stainless steel will not retain odor or taste, and are 100 percent recyclable. All components of the bottles, including the lid are 100 percent BPA free.