Doulton W9121709 10-Inch Super Sterasyl Ceramic Gravity Filter Candle Candles have a domed end and a plastic mount on the top to fix them into the filter housing W9121709 cleanable filter elements are designed toreduce suspended solids, pathogenic bacteria, organic chemicals, and improve taste and odor At the heart of every Doulton ceramic filter is the "Sterasyl" silver impregnated ceramic micro filter