What Our Gearhead(R) Experts Are Saying:"I swapped in the BeFree AC Bottle Replacement Cart after a long season of heavy use, and the difference was immediate. The EZ-Clean Membrane dropped right in and had my BeFree AC Bottle filtering cleanly again without any hassle at the trailhead."When the filter has done its job and then some, the BeFree AC Bottle Replacement Cart from Katadyn gets your BeFree AC Bottle back to full performance without replacing the whole setup. The EZ-Clean Membrane filters up to 1000 liters, depending on water quality, giving you a long run of reliable, clean water before the next swap is even a thought.