Amazing water bottle. I am always looking for a spill-proof, easy, dynamic water bottle to tag along with me wherever I go. This one is fantastic. It works just like the camelbak water system in that you bite the rubber end of the mouth-piece to drink, but without the bulk of a backpack. The mouth acts as a straw making it easy and almost fun to use. I like any product that compels me to drink more water and this little guy definitely does.