16" x 28" or 28" x 16" Cube Core Eggcrate Return Air Grille Insulated Line Set + Product Details Size –

+ Product Details Size – 25"w X 34"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 12 5/8" width X 34 5/8" height

+ Product Details Size – 30"w X 20"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

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 12" or 12" x 10" duct opening (measured at the opening)

16" x 28" or 28" x 16" Cube Core Eggcrate Return Air Grille Insulated Line Set + Product Details Size –+ Product Details Size 16" x 28" or 28" x 16" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 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