Berkey Shower Filter with Massaging Shower Head - Reduces up to 95% of chlorine Reduces up to 95% of chlorine Reduces chemical absorption and vapor inhalation Berkey shower filters typically last (approx.) one year or 20,000 gallons (whichever comes first) before a replacement is needed Reduces lime, scale, mold and fungi in showers Back flush attachment included to prevent premature clogging. Do not use with Shut-off valve