26" x 34" or 34" x 26" Cube Core Eggcrate Return Air Grille return grille + Product Details Size -

+ Product Details Size - 22"w X 36"h is the size for the duct opening measurement only

+ Product Details Size - 28"w X 6"h is the size for the duct opening measurement only

For 8" Round Duct Opening - Spiral or Flex

+ Product Details Size - 20"w X 30"h is the size for the duct opening measurement only

26" x 34" or 34" x 26" Cube Core Eggcrate Return Air Grille return grille + Product Details Size -+ Product Details Size 26" x 34" or 34" x 26" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 27. 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