Grayl GeoPress

“Grayl Ultrapress Pros: * Nice form factor * Easy to use * Effective filtering * It is extremely convenient to be able to drink from tap water anywhere I travel to using this bottle, no need to buy bottled water. Cons: * When exposed to any change in air pressure, the water back flows and leaks out of the bottle. This happens on planes, and also in the car when you drive up/down a mountain. Or even just left in a car that is subject to heating and cooling from the sun during the day. Cup holder always ends up wet. * Due to the first con, I can't really use it as a bonafide water bottle, but only as a manual pressure filter system. I end up filtering the water and pouring it into a 48 fl oz Nalgene bottle for storage and use * Given that, I would have been better off buying the larger Geopress than the smaller Ultrapress, just to use it as a hand-pump filter. * Although they say you can dry the filter and store it for future use, I tried it and when I tried to re-use it several months later, water won't flow through it anymore - when I press it, water leaks out the side instead of going through the filter. This filter was only used to filter tap water for a couple of weeks, so it was very clean to begin with. So I end up having to spend a lot more on the filter cartridges.”