Constructed of 18/8 stainless steel, this 21 oz. bottle features TempShield™ double-wall vacuum insulation to keep beverages cold for up to 24 hours and hot for up to 12 hours. The advanced insulation also prevents condensation from cold beverages and heat transfer from hot beverages so that you can always comfortably handle the bottle. Easy to clean and highly resistant to odors and bacteria. BPA-free and Phthalate-free. Lifetime warranty from the manufacturer.