The Katadyn Replacement Cartridge for the Katadyn Microfilter Bottle and My Bottle microfilter has a 0.3 micron filter design to allow for fast water flow. Always keep an extra on hand, to assure you have a source for safe drinking water. Replacement cartridge for Katadyn Microfilter Bottle and My Bottle. 0.3 micron filter. ViruPur glassfiber filter with depth filtration, fiberglass pre filter and carbon filter. Removes Giardia, Cryptosporidium, and bacteria to EPA standards. Cartridge capacity up to 26 gallons, depending on water quality.