22" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar + Product Details Size –

+ Product Details Size – 12"w X 16"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 26 5/8" width X 26 5/8" height

actual front end outer dimensions are approximately 36 5/8" width X 30 5/8" height

actual front end outer dimensions are 15

+ Product Details Size – 18" x 28" or 28" x 18" is the size for the duct opening measurement only

22" x 18" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Aluminum Bar + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 22" x 18" OR 18" x 22" duct opening (measured at the opening), with actual outer dimensions of 24. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 21. 75" x 17. 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