Replacement filter for SpaceGuard-2400. Replacement Expandapac™ Media Filters are for use in research products cabinet models 2200, 2250 and 2400. 16 x 27-1/8 x 5-7/8 inch. High filtration efficiency. Low pressure drop. Easy to install. Long life. UL listed. Minimum Efficiency Reporting Value (MERV)-10. Efficiency ranges are defined for small particles, E1 = 0.3 to 1.0 microns; medium particles, E2 = 1.0 to 3.0 microns; and large particles, over 3.0 microns. Fractional efficiency: E1=19%, E2=54%, E3=86%.