Sterling Seal KP-5251104791 Purolator Key Pleat Extended Surface Pleated Air Filter, Mechanical MERV 8, 19.50" Height, 1.75" Thick, 24.50" Width (Pack of 12) Mechanical MERV8 filter; Air flow capacity listed at 500 FPM Low initial resistance for energy savings, quality engineered and consistently produced Single piece beverage board die cut frame with structural integrity ACTUAL SIZE: 19-1/2" Width X 24-1/2" Height X 1-3/4" Thick, NOMINAL SIZE: 20" Width X 25" Height X 2" Thick