9.5x23.5x.75 actual size (10 x 24 x 1 nominal size). The 10x24x1 air filter is an extended surface pleated filter, which exceeds ordinary air filters with medium efficiency, and are engineered for decreased pressure drop, and increased service life, which reduces HVAC equipment maintenance and energy expenses. The 10x24x1 air filter is rated to ASHRAE test standards 52.2, which assures that the air filter will operate as good or better than original manufacturer 10x24x1 air filters. Pleated design. MERV classified to ASHRAE ratings. 492 cfm flow rate.