The all-new Purist Insulated features our Chromatekª liner—a proprietary insulating barrier that lines the core to keep your liquids cold. Not only do your liquids stay cold, but new squeezable materials allow for unmatched flexibility, too. The Purist Insulated Chromatekª bottles still feature an amorphous silicon dioxide coating that's infused into the inner-wall of the bottle. Essentially, this forms a glass-like finish that provides a totally natural, and completely inert, solution to the problem of your drinks staining the bottle or leaving behind any residual aftertaste. This infusion also shields your fresh water from tasting like plastic on very hot days, making it akin to drinking straight from a sparkling clean glass. Finally, our Watergate cap features our Heart Valveª that opens and closes—hands-free.