18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille return filter + Product Details Size –

+ Product Details Size – 6"w X 14"h is the size for the duct opening measurement only

Actual Filter Size – 31 3/4"w x 33 3/4" x 1"

baffles and plaster frames available

actual front end outer dimensions are approximately 32 5/8" width X 32 5/8" height -

18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille return filter + Product Details Size –+ Product Details Size 18" x 28" or 28" x 18" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 75" X 29. 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