Sterling Seal KP-5251525519 Purolator Key Pleat Extended Surface Pleated Air Filter, Mechanical MERV 8, 15.50" Height, 3.75" Thick, 24.50" Width (Pack of 6) 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: 15-1/2" Width X 24-1/2" Height X 3-3/4" Thick, NOMINAL SIZE: 16" Width X 25" Height X 4" Thick