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

+ Product Details Size – 16"w X 20"h is the size for the duct opening measurement only

and sound level range of NC 25 to 35

actual front end outer dimensions are approximately 10 5/8" width X 16 5/8" height

Actual Filter Size – 21 3/4"w x 13 3/4" x 1"

Installation of the vents will eliminate the need to raise the door ensuring security and constant air flow and reduced heat transfer into attics and adjacent house walls

18" x 28" or 28" x 18" Cube Core Eggcrate Return Air Grille white + 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