The Hydro Flask Wide-Mouth Vacuum Insulated Stainless Steel Water Bottle offers double-wall vacuum insulation that keeps the contents hot up to 6 hours or cold up to 24 hours. Wide-mouth opening makes it easy to clean or add ice cubes. It is made from durable 18/8 food-grade stainless steel is BPA-free, non-porous, odor and bacteria-resistant. The new Flex Cap is insulated to further protect the beverage from outside temperatures. This Hydro Flask Insulated Water Bottle is available in 18, 32, 40, and 64 oz. sizes. It is perfect for all-day hydration.