30" x 16" or 16" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Diameter Actual Filter Size – 29

Actual Filter Size – 29 3/4"w x 35 3/4" x 1"

+ Product Details Size – 26"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 24"w X 4"h is the size for the duct opening measurement only

4" X 10" Is The Size For The Duct Opening (floor/vent hole) Measurement Only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 14" x 12" or 12" x 14" duct opening (measured at the opening)

30" x 16" or 16" x 30" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Diameter Actual Filter Size – 29+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 16" OR 16" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 75" x 15. 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