LifeStraw Peak Series Membrane Microfilter ReplacementCompatible 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.