16" x 36" or 36" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Black + Product Details Outer dimensions:

+ Product Details Outer dimensions: 31

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

+ Product Details Size - 28"w X 12"h is the size for the duct opening measurement only

Filter grille features a user-friendly plastic latch that requires no screwdriver for opening

Ideal for Walls & Ceilings: Designed for seamless installation in standard 24" X 4" duct openings

16" x 36" or 36" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Black + Product Details Outer dimensions:+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 36" OR 36" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 35. 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