8" x 24" or 24" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 26.5"] 10in diameter + Product Details Size –

+ Product Details Size – 10" x 20" or 20" x 10" is the size for the duct opening measurement only

Design – This airflow control component are made to connect to HVAC diffuser and restrict airflow

if your hole is 20" wide by 14" tall

making it ideal for preventing tampering or unauthorized adjustments

Actual Filter Size – 11 3/4"w x 21 3/4" x 1"

8" x 24" or 24" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 26.5"] 10in diameter + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 24" or 24" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 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