12" x 26" or 26" x 12" Cube Core Eggcrate Return Air Grille 18" Round Duct Pipe the actual front end outer

the actual front end outer dimensions are 6" in diameter

6" x 6" - opening (vent hole - Neck Size) dimension - actual size is approx 2" wider

+ Product Details Size – 8" x 16" or 16" x 8" is the size for the duct opening measurement only

+ Product Details Size - 18"w X 24"h is the size for the duct opening measurement only

12" x 26" or 26" x 12" Cube Core Eggcrate Return Air Grille 18" Round Duct Pipe the actual front end outer+ Product Details Size 12" x 26" or 26" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 27. 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