18" x 24" or 24" x 18" Cube Core Eggcrate Return Air Grille Fixed Blades + Product Details Size –

+ Product Details Size – 26" x 30" or 30" x 26" is the size for the duct opening measurement only

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

Actual Filter Size – 25 3/4"w x 7 3/4" x 1"

14"w X 2"h Is The Size For The Duct Opening Measurement Only

18" x 24" or 24" x 18" Cube Core Eggcrate Return Air Grille Fixed Blades + Product Details Size –+ Product Details Size 18" x 24" or 24" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 25. 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