12" x 14" or 14" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 16.5"] w25h25 function toggleAccordion(event) { event

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

so you are not left with much waste

+ Product Details Size - 20"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 24 5/8" width X 32 5/8" height

12" x 14" or 14" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 14.5" X 16.5"] w25h25 function toggleAccordion(event) { event+ Product Details Perfect Fit & Easy Sizing Designed for a 12" x 14" or 14" x 12" duct opening (measured at the opening), with actual outer dimensions of 14. 5" W x 16. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 11. 75" x 13. 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