This bottle is amazing. I never believed it could keep drinks cold for 24 hours, especially as the quantity goes down and the drink is exposed to more air inside, but it still stayed cold! The only reason I don't give 5 stars is because you have to account for the weight and it's not easy to carry. With the drink inside it's quite heavy, and wet with condensation so not suitable for running, bike riding etc. But perfect otherwise and certainly everybody that's seen mine now wants one.