Oval Air Filter Cartridge 1, It provides up to 25 percent more filtration air flow than other same-sized cartridge. 2, Shorter and stiffer filter pleats help minimize dust entrapment simplify filter cleaning. By reducing the height of the pleats from the standard 2 inches to 1.5 inches, the pleat wall is less likely to collapse or bend, which can encapsulate dust and prevent it's expulsion. Meanwhile cost was reduced. 3, Oval-shaped cartridge filters have fewer areas of high velocity, resulting in a lower potentially for media abrasion and increased filter life.