36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w14h14 this guard fits almost any

this guard fits almost any thermostat and blends seamlessly into any setting

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings

+ Product Details Size - 26"w X 4"h is the size for the duct opening measurement only

Actual Front End Outer Dimensions Are 3

36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w14h14 this guard fits almost any+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 24" OR 24" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 23. 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