16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 10" this grille enhances air circulation

this grille enhances air circulation

+ Product Description Secure your thermostat with the heavy-duty Beige Metal Thermostat Guard

+ Product Details Size - 34"w X 36"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 22 5/8" width X 42 5/8" height -

gymnasiums & restaurants

16" x 18" or 18" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Compatible with Duct 10" this grille enhances air circulation+ Product Details Perfect Fit & Easy Sizing Designed for a 16" x 18" OR 18" X 16" duct opening (measured at the opening), with actual outer dimensions of 18. 5" W x 20. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 15. 75" x 17. 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