iSpring WCB32O 3-Stage 20" Whole House Water Filter With 3/4 inch NPT Carbon Three Stages of filtration in 20" housings Removes a wide range of contaminants, including Sediment, Chlorine and Organic chemicals 3/4" inlet/outlet Pressure Release Button for fast release of the whole house water filter pressure Standard replacement cartridges 2.5" x 20" (one set of three is already included: 1 Sediment + 2 CTO Carbon)