16"w X 20"h Steel Return Air Grilles - Sidewall and Cieling - HVAC DUCT COVER - Brown [Outer Dimensions: 17.75"w X 21.75"h] 16"w X 20"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 17.75" Width X "w X 21.75" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLE 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 Easy Unrestricted Air Flow For Your HVAC System - 50 angled to provide maximum airflow Powder-Coat Finish - Smooth, Shiny, Scratch-Resistant, Beautiful. Looks Like It Was Just Waxed