A filter element that has at least two, planar, non-curved filtration panels. In a preferred embodiment, the filter element has three panels, providing a generally triangular filter element. The outlet aperture, from the filter element, generally follows the configuration of the filter. That is, a filter element having three filtration panels will have a generally three-sided outlet aperture. The outlet aperture preferably is not a true polygon, but rather, includes rounded or curved sides and/or corners. The filter element includes an outlet sealing configuration that may provide both axial and radial sealing to outlet ductwork.