The double wall insulation will keep your liquid cold for up to a full day (as well as keep drinks warm for up to 12 hours). The coat never sweats, the bottle itself is stainless steel and BPA-free, and each flask comes with a lifetime warranty. What’s even better, Hydro Flask gives five percent of each purchase to a charity of your choice. Basically, buying something that can fuel your drinking habit actually gives back. We’ll drink to that.