SH Naiture 14" X 14" Wood Premier Wood Air Return Grille Duct opening size: 14 by 14 Inch (16-7/8"X15-5/8" Overall) Made from New Zealand pine with Baltic birch plywood louver frame. Fits most standard openings with little or no wall modifications. 26-gauge metal housing for grille and filter. Each grille has 2 coats of oil-base primer. May be painted to match wall color. Paint exposed and concealed surfaces before installing. To determine size needed, measure existing air filter size rather than old register or grille. See more details in the product description as below.