Hydro Flask 21 oz Insulated Water Bottle - Standard Mouth The 21 oz is ideal for taking on the weekend bike ride or hike to keep your fluids cold. Or take it up the mountain and have coffee, hot cocoa, or hot soup waiting for you at the end of the day. The standard mouth features a larger opening than our original narrow mouth bottle. The 21 oz insulated bottle is made from 18/8 food-grade stainless steel and the double wall vacuum insulation provides top notch insulation power, keeping cold liquids icy cold for up to 24 hours and hot liquids steaming hot for up to 12 hours. Hydro Flask products are BPA-free, 100% recyclable and are backed by a lifetime warranty. Look for the Hydro Flask logo to ensure you’re getting the market’s premium insulating beverage bottle. Product Features: Keeps Hot up to 12 Hours Keeps Cold up to 24 Hours Double Wall Vacuum Insulated BPA-Free 18/8 Stainless Steel Signature Powder Coat Finish in 12 colors Lifetime Warranty