14.5X24.5X.75 actual size (15 x 25 x 1 nominal size). This 15x25x1 air filter is an extended surface pleated filter, which exceeds ordinary air filters with medium efficiency, and are designed for decreased pressure drop, and increased service life, which reduces HVAC equipment maintenance and energy expenses. Our 15x25x1 air filter is measured to ASHRAE test standards 52.2, which ensures that the air filter will capture particulate as good or better than OEM 15x25x1 air filters. Pleated design. MERV rated to ASHRAE classifications. 768 cfm flow rate.