28" x 34" or 34" x 28" Cube Core Eggcrate Return Air Grille 18" Round Duct Pipe + Product Details Size –

+ Product Details Size – 20"w X 22"h is the size for the duct opening measurement only

ensuring it fits most standard thermostat models

14"w X 3"h Is The Size For The Duct Opening Measurement Only

with actual outer dimensions of 14

28" x 34" or 34" x 28" Cube Core Eggcrate Return Air Grille 18" Round Duct Pipe + Product Details Size –+ Product Details Size 28" x 34" or 34" x 28" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 29. 75" X 35. 75". High Quality High quality, rust free aluminum construction with smooth finished edges and counter sunk screw holes (screws included); no sharp edges.. Installation Location sidewall and ceiling. Design Cubic core eggcrate design Offers highest airflow efficiency at almost 95%, reducing