This Sprite Hand-Held or Hose Filter Replacement Cartridge is a reversible 3-month filter cartridge. There are 2 cartridges per pack giving you 6 months of chlorine free showers per package. Its unique Chlorgon and KDF filtration media means it will filter out total chlorine - both free and combined - providing for enhanced chlorine removal protection. It can be easily reversed and operated in both directions. Periodic reversing of the cartridge not only eliminates channeling (ensuring balanced filtration) but also back-flushes the filter.