The MSR Guardian Purifier is a premium portable water filter designed for outdoor enthusiasts who require reliable filtration technology. With a filter life of 10,000 liters, this water purifier offers superior purification capabilities. Made in the United States, it utilizes polypropylene filtration technology to effectively remove contaminants from water sources during camping, hiking, and other outdoor adventures. The compact size of 8.2 x 4.7 x 3.5 inches makes it convenient to carry and use on the go, ensuring clean and safe drinking water in remote environments. This unit is sold as 'used', but it's only ever been used once - to test the unit, so there is still the full life expectancy.