20" x 36" or 36" x 20" Cube Core Eggcrate Return Air Grille Insulated Line Set Actual Filter Size – 33

Actual Filter Size – 33 3/4"w x 17 3/4" x 1"

+ Product Details Durable Construction - Made with clear

+ Product Details Size – 34"w X 26"h is the size for the duct opening measurement only

Actual Filter Size – 31 3/4"w x 15 3/4" x 1"

actual front end outer dimensions are approximately 10 5/8" width X 14 5/8" height

20" x 36" or 36" x 20" Cube Core Eggcrate Return Air Grille Insulated Line Set Actual Filter Size – 33+ Product Details Size 20" x 36" or 36" x 20" is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 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