6" x 36" or 36" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 8.5" X 38.5"] Adjustable Return Made from high-grade stamped steel Ducting Components RG2016 FBA-HP Applications The C box

Made from high-grade stamped steel

+ Product Details Size – 24"w X 36"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 22" or 22" x 12" duct opening (measured at the opening)

very easy to do

actual front end outer dimensions are approximately 18 5/8" width X 22 5/8" height

6" x 36" or 36" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum White [Outer Dimensions: 8.5" X 38.5"] Adjustable Return Made from high grade stamped steel Ducting Components RG2016 FBA HP Applications The C box Made from high grade stamped steel + Product Details Size – 24"w X 36"h is the size for the duct opening measurement only