1.Only for use in models CB-As 2.Please note that the replacement filters listed here are NOT interchangeable with other water filtration systems 3.CB Tech Carbon Block filters utilize a combination of mechanical filtration, electrokinetic adsorption, and physical/chemical adsorption to reduce a wide range of contaminants of health concern. 4.Genuine CB Tech replacement filters have been tested and certified to reduce Arsenic, chlorine, chloramine, tastes and odors, particulate matter, as well as cysts, VOCs, MTBE, trihalomethanes, heavy metals (lead, mercury) turbidity, certain pesticides and asbestos.