Junior Style Filter Cartridges Junior style filter cartridges are available with a variety of filtration media and pore size ratings for both pre-filtration and final filtration applications. The following sections provide product descriptions and specifications.Specification MaterialMembranePP, PES, PTFE, PVDF, N6\N66, PP,GFDiversion layerPP fiber or polyester fiberHousingPPInner supportPP ...