Enjoy hot or cold liquids in this portable and durable bottle! The 21oz. 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 soup waiting for you at the end of the day. The standard mouth features a larger opening than the original narrow mouth bottle. It is ideal for coffees, teas, mixing sport drinks or just for those who need to take in more hydration, more quickly. They fit perfectly in most car, bicycle and stroller cup holders and water bottle cages. These stainless steel water bottles perform in every environment. Each Hydro Flask is hand cast from double wall vacuum insulated food grade 18/8 stainless steel, therefore they are BPA-Free and resistant to bacteria and odors. Using double wall vacuum insulation technology, Hydro Flasks keep contents hot for 12 hours and cold for 24 hours. Look for the silver ring on the neck of every Narrow Mouth and Standard Mouth Hydro Flask to ensure you're getting the best performing water bottle on the market.