18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 + Product Details Size –

+ Product Details Size – 24" x 26" or 26" x 24" is the size for the duct opening measurement only

making it ideal for preventing tampering or unauthorized adjustments

powder-coated surface is scratch-resistant

Actual Filter Size – 11 3/4"w x 5 3/4" x 1"

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

18" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w18h18 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 18" x 6" OR 6" X 18" duct opening (measured at the opening), with actual outer dimensions of 20. 5" W x 8. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 17. 75" x 5. 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 Made