16" x 18" x 2", Pre-Pleat 40 Air Filter, 100% Synthetic, High Dust Holding Capacity & Low Pressure Drop, 2 Piece Heavy Duty Die Cut Frame, Expanded Metal Backing & Diagonal Grid Supports For Maximum Strength, MERV Rating 8, 90 Day Filter, Effective Against Pollen, Dust/Lint, Dust Mites, Pet Dander, Mold, Bacteria, Virus Carriers.