The F118 was designed for commercial drop ceilings, especially those with little room to spare above. It fits standard two by four foot openings and is flush with the ceiling. Its attractive white grille blends into any decor, and the grille swings down for easy access to the prefilter, media filter and sorbent media. You'll find the F118 well suited for use in employee lounges, day care centers, nursing homes, cafeterias - any area, in fact, where both aesthetics and efficiency are important.