This 10" KDF85 Carbon Filter augments Hydrologic's Stealth RO System by greatly increasing its ability to filter chlorine, chloramines, iron, hydrogen sulfide and heavy metals, making it a great choice for city-dwellers and well water. This KDF85 Filter is ideal for well water users with high iron and sulfur and city water users with chloramines. Simply replace your original Stealth green Carbon filter with this KDF Filter. For use with Stealth RO 100 & 200. Doubles standard green carbon filter. Bacteriostatic qualities do not allow microbes to breed in filter.