20" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Return + Product Details Size -

+ Product Details Size - 18"w X 24"h is the size for the duct opening measurement only

Filter Size - 23

Made of High Quality Aluminum That Will Never Rust

See our separate listing for Butterfly Dmaper to Control Airflow

+ Product Details Size – 26" x 34" or 34" x 26" is the size for the duct opening measurement only

20" x 26" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Return + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 26" OR 26" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 28. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 25. 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