26" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Round Damper Ring Actual Filter Size – 15

Actual Filter Size – 15 3/4"w x 25 3/4" x 1"

+ Product Details Size – 36"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 18"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 34 5/8" width X 22 5/8" height

actual front end outer dimensions are approximately 24 5/8" width X 27 5/8" height

26" x 8" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Round Damper Ring Actual Filter Size – 15+ Product Details Perfect Fit & Easy Sizing Designed for a 26" x 8" OR 8" x 26" duct opening (measured at the opening), with actual outer dimensions of 28. 5" W x 10. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 25. 75" x 7. 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