36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Outdoor Vent Covers + Product Details Size –

+ Product Details Size – 12"w X 20"h is the size for the duct opening measurement only

these louvers are built to last

+ Product Details Size – 26"w X 16"h is the size for the duct opening measurement only

See our separate listing of T-Bar Supply Grilles

36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Outdoor Vent Covers + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 24" OR 24" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 23. 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