What a lovely design! If you've wanted to use a re-usable water bottle but hated the clunky design, here's something for you. 321 Water is a beautifully designed water bottle that has a unique plunger mechanism with a built-in filter so you can turn any tap water into filtered water. Not only will you help the environment, you'll have fresh, filtered water right at your fingertips. It's like your personal, portable Brita.