After many, many adventures, we restore flow rates in our MSR HyperFlow Microfilter with the Hyperflow Microfilter Cartridge Replacement. We just pop the replacement in to get fresh, fast water purification on our next backcountry excursion. This filter cartridge lasts for up to 1,000 liters of pumping depending on water conditions, and can be cleaned in the field to keep your filter flowing strong.