26" x 36" or 36" x 26" Cube Core Eggcrate Return Air Grille Compatible With Duct 8in Actual Filter Size – 31

Actual Filter Size – 31 3/4"w x 5 3/4" x 1"

actual front end outer dimensions are approximately 30 5/8" width X 8 5/8" height

+ Product Details Size - 4"w X 34"h is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 20" X 6" duct openings

Operating from -40°F to +248°F

26" x 36" or 36" x 26" Cube Core Eggcrate Return Air Grille Compatible With Duct 8in Actual Filter Size – 31+ Product Details Size 26" x 36" or 36" x 26" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 27. 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