The Practical Pleat Grille Filter is a 5” high performance filter designed to replace inferior 1” filters. Its unique gasket fits into one-inch filter grilles with the excess depth of the filter protruding into the duct system. The Practical Pleat’s surface area is 433% greater than a comparable 1” extended surface pleat, and the effective lifetime is up to four times greater. Don’t let the competitors fool you! The Practical Pleat is the only retrofitting filter with its unique gasket to prevent air bypass. Gaps between the filter and filter frame allow particles to be pulled around the filter, entering the duct system and ultimately, inhabited spaces.The “Practical Pleat’s” unique patented gasket conforms to imperfections in the filter track, eliminating air by-pass, and preserving the integrity of the MERV 11 or MERV 14 rating.