26" x 28" or 28" x 26" Cube Core Eggcrate Return Air Grille Fixed Blades Design – These are specially

Design – These are specially sized to fit into all drop ceilings

+ Product Details Size - 18"w X 12"h is the size for the duct opening measurement only

Installation Location – Sidewall and ceiling

Ideal for Walls & Ceilings: Designed for seamless installation in standard 20" X 20" duct openings

Actual Filter Size – 7 3/4"w x 29 3/4" x 1"

26" x 28" or 28" x 26" Cube Core Eggcrate Return Air Grille Fixed Blades Design – These are specially+ Product Details Size 26" x 28" or 28" x 26" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 27. 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