The Carrier FILXXCAR0024 compatible filter fits the Carrier FILCAB mechanical air cleaner, MPKA series and any other 24"L x 25"W x 5"T box filter. This media filter is a whole house filter which is attached to the HVAC system. It has a MERV 8 efficiency value, which indicates how minute the particles are that can be trapped by it. The higher the value, the smaller the size of particles filtered and higher the number of particles captured. It is 20 times more efficient at trapping particles than a fiberglass filter. This filter has a pleated rather than a flat surface, thereby increasing the surface area which further increases the number of contaminants it can capture. With a MERV 8 value, this filter traps airborne pollutants as small as 3.0 microns such as dust, pollen, dust mites, and animal dander while allowing a free flow of cleaner air. An additional benefit is that it will also extend the life of your heating and cooling system by making it work more efficiently by preventing the accumulation of particles that settle on the evaporator and condenser coils.