This Kwik-Change (TM) Lead Reduction Filter is designed to fit the Pure Water model number PWDWHCL1 under counter water filtration system. With a 2 GPM flow rate, the PWDWHCL1 system is certified to reduce lead, cyst, chlorine, taste, odor, sand, silt, dirt and rust. This replacement filter is designed for easy and quick filter replacement with just a quarter turn. For best results, it should be changed every year or 7,900 gallons.