30" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grilles Actual Filter Size – 23

Actual Filter Size – 23 3/4"w x 29 3/4" x 1"

Ideal for Walls & Ceilings: Designed for seamless installation in standard 20" X 8" duct openings

+ Product Details Size – 18"w X 24"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 12" OR 12" x 20" duct opening (measured at the opening)

The 1/2" black insulation

30" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Grilles Actual Filter Size – 23+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 6" OR 6" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 8. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 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