Naiture 8" x 14" Single Deflection Wood, Cold Air Return Vent Cover Grille, Unfinished Red Oak Duct opening size: 6" x 11-1/4" (8" x 14" Overall) Made of high-quality 3/4"-thick unfinished red oak wood Fits flush with floor. Made specifically for hardwood floors. Single piece, come with no frame. This return vent has a simple and clean design. The single deflection air flow could also be used as a wall mount application. To determine size needed, measure air duct opening rather than old register or grille.