Doulton W9121750 Supersterasyl Undersink Ceramic Candle Replacement Filter CartridgeThe Doulton W9121750 10 inch Super Sterasyl Ceramic Filter Candle features three stages of filtration in a single cleanable cartridge. The candle design features a domed end and a plastic mounted top with 3 4 inch long thread mount, for a perfect match every time in your non gravity fed Doulton system's HIP HCP HIS housing. It reduces suspended solids, iron, hydrogen sulfide and other trace contaminants, as well as improving taste.