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.