[NSF CERTIFICATION] Certified and tested to NSF/ANSI 42 standard to reduce chlorine, odor and retain beneficial minerals in your water.   [USEFUL LIFE] For peak efficiency of your filtration system, it is recommended to remove approximately 4 gallons of water before the initial usage. Enjoy fresh by replacing every 6 months or 200 gallons, whichever comes first.     [EASY REPLACEMENT] Easy for installation and operation, without water leakage and connection issues.   [NOTE] You'll notice the central plastic piece different from the OEM. While this might raise concerns initially, I encourage you to try it out – you'll discover it inserts effortlessly and operates seamlessly.   [REPLACEMENT MODEL] Replacement for WF3CB, Pure Source 3, WF425, 706465, 242069601, 242086201, 242017800, PS3412266, AP4567491.