Review on Stay Hydrated On-The-Go With HydraPak Seeker Collapsible Water Storage - Safe, Portable And Ideal For Camping by David Gill

I really liked the Katadyn BeFree filtration system, but I didn't like how they only offer a 0.6L or 1.0L bottle. Having a collapsible bottle is good for that system, mainly because you want to be able to squeeze every last drop of water out. I tried another Hydrapak bottle (0.7L) which still seemed too small (also, it leaked at the junction where the mouthpiece and bottle met) -- I was refilling it more often than I would like. So, I called Katadyn and asked them what my options were. They pointed me to the Hydrapak Seeker. This is a much more rugged bottle than the other Hydrapak bottles. The walls just feel like they can take a beating. It's still collapsible into a small pouch, which comes with the bottle. More importantly, it doesn't leak, and it seems to be a great size for backpacking and filtering water without having a bottle that's too bulky to use, but you also don't need to refill constantly.