Showering in chlorinated water, a chemical frequently found in water supplies, can strip the oil from the hair causing it to become fragile and crack and causing skin to dry and crack, leading to permanent signs of aging. Showering in filtered water help stop these damaging effects. The Westbrass SHF filter provides triple action filtration remove impurities, heavy metals such as lead, mercury, organic chemicals like hydrogen sulphide and chlorine and other harmful substances from your water while enhancing the water's cleansing abilities by releasing beneficial natural minerals that the human body needs. The filters still allow for a 1.8 GPM flow rate. Filter cartridges should be replaced every six (6) months, 10,000 gallons or if it begins to discolour. They are sold as two-packs. HHF Replacement filter unit is compatible with Westbrass models: SCH900F, F730, HSF731 and HSF6701. SHF Replacement filter unit is compatible with Westbrass models: SCH900F, SHF5700 and SAF. Replacing the cartridge is quick and easy, just swap the old cartridge with a new one, flush with hot water for one (1) minute, and it’s ready for use. Westbrass Fine Decorative Plumbing since 1935.