The 2-stage LifeStraw Go series replacement filter includes both a membrane microfilter and activated carbon filter. This replacement water filter is only compatible with LifeStraw Go series water bottles which include a top lid that twists on to cover the mouthpiece and were purchased in 2023 or later. This filter removes bacteria, parasites, microplastics, AND reduces chlorine, bad odor, silt, sand, and cloudiness for improved taste. LifeStraw filters are rigorously tested to meet drinking water protocols established by the US Environmental Protection Agency (EPA) and NSF International/ANSI. For every purchase, a child in need receives safe water for a year. FEATURES Compatible with Go series water bottles purchased 2023 or later. Not compatible with earlier models that feature the flip-up mouthpiece and carabiner attachment Protects against bacteria (including E.coli, Salmonella), parasites (including Giardia and Cryptosporidium), microplastics, chlorine, organic chemical matter, silt, sand, and cloudiness; improves taste LifeStraw is proud to be a B Corp and Climate Neutral Certified brand For every purchase, a child in need receives to safe drinking water for a year TECH SPECS STANDARD Meets NSF 42 standard for chlorine reduction & US EPA & NSF P231 drinking water standards for the removal of bacteria and parasites FILTER LIFE Membrane Microfilter: up to 4,000L Activated Carbon: up to 100L