The Doulton W9331032 UltraCarb Countertop Water Filter System features four stages of filtration in a single cleanable cartridge. The candle design features a domed end and a plastic-mounted top with threads for a perfect match every time in your non-gravity-fed Doulton system s housing. It reduces suspended solids lead iron hydrogen sulfide and other trace contaminants as well as improving taste. It also effectively reduces pathogenic bacteria including cholera salmonella and typhoid. The entire system is NSF 42 and 53 Tested and Certified.