The VGPS0.2-20S1-S Shelco MicroVantage VGPS Series vent grade hydrophobic polysulfone membrane filter cartridge. Absolute rated at 0.2 microns. This filter has a nominal length of 20 inches and has a S1 = DOE endcap configuration. The filter has a S = Silicone gasket material to ensure a proper seals to the filter housing. This product is made to order and is non-returnable.