16" x 16" Fixed Bar Return Grille - All Steel Structure - Elegant Look & Sturdy Finish [Outer Dimensions: 17.75"w X 17.75"h] Sidewall and/or Ceiling Grille Easy Unrestricted Air Flow For Youre HVAC System Carefully shrink wrapped with cardboard backing to prevent damage in shipment Screws Included - No Sharp Surface Edges 16" x 16" opening (vent hole) dimension - actual size is approx 2" wider.