Listing includes 3 carbon filters for use on Waterfiller water bottles. Read about water bottles below. Using the WaterFiller filtered water bottle is easy, simply fill it with any potable water - like tap water - and you're ready to enjoy clear, clean-tasting water. The engineering that went into creating the Cleanest Water Bottle on the Planet is anything but simple though. Much research went into finding the perfect design to ensure the cleanest drinking experience ever. The driking straw was designed to comfortably fit your mouth and reduce the amount of suction needed to get a drink. The heart of the bottle is the specially designed hi tech carbon filter. By removing chlorine, bad tastes, and odors, it delivers a pure, clean-tasting drink from ordinary tap water. Even when it comes to cleaning the bottle, design and function were considered carefully. The simple thumb switch holds the mouth piece open for thorough cleaning. And since it's dishwasher safe, cleaning is a breeze!