18" X 18 Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - ceiling Recommended - HVAC DUCT COVER - Flat Stamped Face - White [Outer Dimensions: 20.5"w X 20.5"h] 18"w X 18"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 20.75" Width X 20.75" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLE Our Easy To Use Filter Grille Latch is Powder-Coated BEFORE Installation - And Requires No Screwdriver To Open. High Quality Solid Stamped steel with Counter-Sunk Screw Holes (Screws Included) and No Sharp Edges Carefully shrink wrapped with cardboard backing to prevent damage in shipment Powder-Coat Finish - Smooth, Shiny, Scratch-Resistant, Beautiful. Looks Like It Was Just Waxed