20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] Floor Grille + Product Details Size -

+ Product Details Size - 36"w X 28"h is the size for the duct opening measurement only

+ Product Details Size - 24"w X 14"h is the size for the duct opening measurement only

Filter grille features a user-friendly plastic latch that requires no screwdriver for opening

+ Product Details Size - 22"w X 34"h is the size for the duct opening measurement only

The 1/2" white insulation

20" x 25" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 22.5"w X 27.5"h] Floor Grille + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 25" OR 25" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 27. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 24. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum