Rainshow"r is the pioneer in the shower filter industry, designing and manufacturing shower filters for over 15 years and have thousands of long time customers. Polyester filter element enhances cartridge performance through sediment removal. Installs in minutes - no special tools or professional help required. Replaceable cartridges lasts 6-9 months for a family of four, or an estimated 15,000 to 20,000 gallons of usage. The body should last for several years with proper care. As chlorinated water flows through the unit the dissimilar metals in KDF, (copper and zinc), create a galvanic or electrolytic reaction, which causes the two chlorine ions to combine with a zinc ion to form a harmless zinc chloride. KDF does not hold the chlorine; it changes chlorine from an element into a harmless compound. This shower filter will typically remove more than 90% of the free chlorine. Reduction levels of 95% or above are not uncommon, but no chlorine reduction shower filter can remove consistently at 95% because of temperature and water flow variations. Filter tested and certified by NSF international against NSF/ANSI Standard 177 for the reduction of free available chlorine.Massage shower head included.