The Purist Hydroflo Fixy Bottle features 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.The silicon dioxide coating is a mere 20 nanometers thick which for comparison is less than 5000 times thinner than a human hair. Meanwhile the shape of the bottle feels equally perfect both in the hand and in the cage.This version has our Hydroflo Fixy cap and bottle shape. It features a self-sealing Heart Valve™ that's completely "slosh-proof" on the bike but when you want a drink a squeeze on the bottle delivers a massive rush of water. However you're able to pop the valve down for an absolute leak-proof seal for when you toss full bottles into your race bag. Additionally Hydroflo features a new three-shape design that not only improves the actual handling of the bottle but it also secures its position within your cage. We recommend a simple rinse and dry after use but if you want to wash it take care not to scratch the inner surface of the plastic. Alternatively it'll be fine on the top rack of your machine.