18" X 24 Steel Return Air Filter Grille for 1" Filter - Removable Face/Door - HVAC DUCT COVER - Flat Stamped Face - White [Outer Dimensions: 20.5"w X 26.5"h] 18"w X 24"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 20.5" Width X 26.5" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLE High Quality Solid Stamped steel and No Sharp Edges Our Filter Grille Latch is Easy To Use On Your Fungers And Requires No Screwdriver To Open. Removable Door/Face For Easy Filter Change & Cleaning - Uses a 1" Thick Filter Powder-Coat Finish - Smooth, Shiny, Scratch-Resistant, Beautiful. Looks Like It Was Just Waxed