20" x 28" or 28" x 20" Cube Core Eggcrate Return Air Grille w6h6 Actual Filter Size – 23

Actual Filter Size – 23 3/4"w x 25 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 20" duct opening (measured at the opening)

+ Product Details Size – 24" x 24" with 12" collar T-Bar drop ceiling perforated return grill - metal back casing

75" width X 37

Every part is hand inspected for quality before it is packaged

20" x 28" or 28" x 20" Cube Core Eggcrate Return Air Grille w6h6 Actual Filter Size – 23+ Product Details Size 20" x 28" or 28" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 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