Sterling Seal KP-5251083881 Purolator Key Pleat Extended Surface Pleated Air Filter, Mechanical MERV 8, 11.38" Height, 0.75" Thick, 23.38" Width (Pack of 12) Mechanical MERV8 filter; Air flow capacity listed at 300 FPM Low initial resistance for energy savings, quality engineered and consistently produced Single piece beverage board die cut frame with structural integrity ACTUAL SIZE: 11-3/8" Width X 23-3/8" Height X 3/4" Thick, NOMINAL SIZE: 12" Width X 24" Height X 1" Thick