???Description?? The Pure Source Ultra ULTRAWF is designed with a carbon-based filter to improve your water by removing the odor and taste of chlorine for smoother drinking, making it easy to keep the whole family hydrated; Certified by NSF Standard 42 to reduce chlorine gas, taste and smell; 53 certified to reduce health-related pollutants such as lead, volatile organic chemicals and asbestos; Certified 401, can reduce the emergence of new chemicals; Replacement fridge filters, Replace water and air filter every 6 months for best results. ???Installation Instructions?? 1. Press the push button to open the filter cover 2. Pull the old cartridge downward to remove .