The CamelBak Brook Vacuum 20oz Bottle takes style to your hydration with a sleek new design that stands out against a boring world of cylinders. It features vacuum-sealed double-walled stainless steel that traps temperatures for beverages that stay cold for a full 24-hours, or warm for up to 6. Its curving walls are not only aesthetically pleasing, but they also don't sweat, thanks to their sweat-proof insulation, keeping the bottle comfortable to hold for hours of sipping.