The EZ Flow II filter frame is made from heavy chipboard in a one-piece design that eliminates corner separation. The filtering media is continuous filament spun glass. The synthetic media of the EZ Flow II PSF filter is continuous filament polyester. A resinous bonding agent provides rigidity and resistance to media compression. The EZ Flow II filter is made to function without a retainer by adhering the frame directly to the media, which has a light skin to make it self-retaining. Sealing is accomplished with a resilient hot-melt adhesive running the full perimeter of the frame on both upstream and downstream sides.