It has a filter in the mouthpiece, like a brita filter
You fill it with ordinary tap water and you can use it as long as you like. Every three months you just replace the top.

here

EDIT: changed to different, non-spazzy link.
( b3th Not shit. Not mod., Thu 7 Jul 2011, 10:27, 2 replies, latest was 15 years ago)

Ohhh okay.
that makes sense. I just buy bottled water from the reject shop cos the water on res is chlorinated and I don't like the taste...
(Poppet some assembly required., Thu 7 Jul 2011, 10:29, Reply)

Is it a standard twist top?
I mean could you attach the filter to a Coca Cola bottle for example?

p.s. that website is fucking annoying
( Peej, Thu 7 Jul 2011, 10:31, Reply)

I gave up at 30%

( Naked Ape call me Caitlyn, Thu 7 Jul 2011, 10:34, Reply)

Sorry. I didn't make the website, so I'm not responsible for its content.
I think it is a little bigger than a standard size top. Might fit a Pepsi bottle though. They're a little bigger, usually.

On a weird but related note, I was buying my Diet Pepsi in Morrisons yesterday (admittedly by the crateload) and some random old bloke started lecturing me on how bad it is for my insides.
( b3th Not shit. Not mod., Thu 7 Jul 2011, 10:34, Reply)

He's quite right
I bet if you did make the website it would be even more annoying with 10 times more swirly animations and slidey bits
( Peej, Thu 7 Jul 2011, 10:36, Reply)

I don't drink pepsi or coke.
they're both foul.
(Poppet some assembly required., Thu 7 Jul 2011, 10:41, Reply)

I only drink virgins piss
and only eat swans eyelids
( Peej, Thu 7 Jul 2011, 10:46, Reply)

I don't.
I drink lots of water and tea and juice. :D
(Poppet some assembly required., Thu 7 Jul 2011, 10:53, Reply)