26" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Black + Product Details Size -

+ Product Details Size - 22"w X 18"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 36" OR 36" X 16" duct opening (measured at the opening)

Actual Filter Size – 33 3/4"w x 7 3/4" x 1"

Actual Filter Size – 9 3/4"w x 13 3/4" x 1"

+ Product Details Size – 12"w X 30"h is the size for the duct opening measurement only

26" x 34" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Black + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 34" OR 34" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 36. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 75" x 33. 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