as soon as you put it to your mouth and want to drink from it the tip pushes in and you're not getting any water. Also, I have to agree that the bottle is too hard to squeeze. So between the top pushed in and the bottle too hard to squeeze you're not getting any water. And I bought two of these at some sporting store for hikers. I've yet to find a good water bottle that is easy to drink from, easy to hold and carry. I found the CamelBack bottle even harder to squeeze and drink from. Sheeeesh, just can't get a good drinking bottle any more!