11.5X15.5X.75 actual size (12 x 16 x 1 nominal size). This 12x16x1 air filter is an extended surface pleated filter, which outpaces standard air filters with medium efficiency, and are built for decreased pressure drop, and longer service life, which reduces HVAC equipment maintenance and energy expenses. The 12x16x1 air filter is graded to ASHRAE test standards 52.2, which establishes that the air filter will operate as good or better than original brand 12x16x1 air filters. Pleated design. MERV classified to ASHRAE grades. 393 cfm flow rate.