Yea totally, Sawyer filters fit them nicely too. They're VERY durable, as in I've got one bottle I've carried probably hundreds of miles by now over several trips and it's been dropped and squeezed thousands of times. Looks like a bear chewed it up, but it still does not leak.
Pro tip: you can replace the O-ring that comes with the filter for a durable rubber one used for garden hoses for a real nice fit on the smartwater bottles, and have some extras because the worst is if you lose that seal (or it is damaged) and you are out in the wilderness.
