The Doulton W9220402 Sterasyl OBE Ceramic candle provides absolute micron filtration down to .9 microns. It has a dimension of 11.5? x 2.3? x 2.3?. The ceramic shell is Silver impregnated to inhibit bacteria growth, making the filter self sterilizing. The Doulton W9220402 Sterasyl Slimline 10 Open Both Ends (OBE) is manufactured with the highly efficient and controlled pore structure necessary to remove a wide range of water borne particulate matter bacteria cysts and turbidity. The Doulton 9120562 Sterasyl S 10" Ceramic Candle removes turbidity, E.Coli, Cholera, Typhoid, Cryptosporidium, insecticides, herbicides, phenols, lead, and chlorine.