A filter assembly for filtering fluids includes a housing having a base and a cover having guide structure for assembly. A central cavity is sealed at both its entry and exit by moving elements held by coil springs. The presentation instrument and the shipping indicator are inserted into an envelope that has a first clear window such that the shipping destination address and tracking indicium show through the clear window. Preferably, the tubular axle beam is constructed by stamping a first blank to form a first half of the beam, and a second blank is stamped to form a second half of the beam.