The W9221000 Imperial SuperSterasyl OBE Ceramic Filter has all the features of the Imperial Sterasyl plus Chlorine reduction and Organics reduction The Doulton W9221000 OBE Filter has a Sterasyl ceramic outer shell with a GACcore This Ceramic Filter is a self-sterilizing filter that can be re-used over and over again to provide absolute micron filtration down to .9 microns