28" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w12h12 + Product Details Size –

+ Product Details Size – 20"w X 24"h is the size for the duct opening measurement only

actual front end outer dimensions are 21

Actual Filter Size – 21 3/4"w x 23 3/4" x 1"

+ Product Details Size - 25"w X 25"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 34 5/8" width X 14 5/8" height

28" x 16" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w12h12 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 16" OR 16" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 15. 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