28" x 30" or 30" x 28" Cube Core Eggcrate Return Air Grille Compatible With Duct 12in but still very thin

but still very thin

+ Product Details Size – 12" x 30" or 30" x 12" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 22 5/8" width X 27 5/8" height

so you are not left with much waste

+ Product Details Size – 24" x 28" or 28" x 24" is the size for the duct opening measurement only

28" x 30" or 30" x 28" Cube Core Eggcrate Return Air Grille Compatible With Duct 12in but still very thin+ Product Details Size 28" x 30 or 30" x 28" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 29. 75" X 37. 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