A filter cartridge for use in separating a hydrophobic liquid aerosol phase from a gas stream, as a crankcase ventilation filter for example, is described. The cartridge includes a media pack comprising filtration media surrounding an open interior and a first end piece. Various structure included on the first end piece is described. An example is a D-shaped projection. Also described is an assembly including the filter cartridge, specific features of a housing component of the assembly. Methods of assembly and use are also described.