MSR Sweetwater Filter Cartridge

The heart of the SweetWater microfilter is a replaceable 0.2-micron labyrinth depth filter with a Filter Replacement Safety Indicator imbedded inside the filter material. After repeated cleanings, this screen-like layer becomes visible so you know when it's time to replace your filter cartridge. A layer of granular activated carbon surrounding the filter improves the taste of unsavory water.