12" x 22" or 22" x 12" Cube Core Eggcrate Return Air Grille return filter 75" Width X 9

75" Width X 9

+ Product Details Size - 28"w X 10"h is the size for the duct opening measurement only

75"H – fits a 14" X 8" duct opening

For 10" Round Duct Opening - Spiral or Flex

12" x 22" or 22" x 12" Cube Core Eggcrate Return Air Grille return filter 75" Width X 9+ Product Details Size 12" x 22" or 22" x 12" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" X 23. 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