8" x 12" or 12" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 14.5"] steel Actual Filter Size – 23

Actual Filter Size – 23 3/4"w x 19 3/4" x 1"

actual front end outer dimensions are approximately 30 5/8" width X 38 5/8" height

+ Product Details Size - 30"w X 34"h is the size for the duct opening measurement only

Measure the size of the air duct/drywall opening

actual front end outer dimensions are approximately 28 5/8" width X 18 5/8" height

8" x 12" or 12" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter - Aluminum - White [Outer Dimensions: 10.5" X 14.5"] steel Actual Filter Size – 23+ Product Details Perfect Fit & Easy Sizing Designed for a 8" x 12" or 12" x 8" duct opening (measured at the opening), with actual outer dimensions of 10. 5" W x 14. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 7. 75" x 11. 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