32" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w14h14 It has an outer surface

It has an outer surface made of high-quality aluminum foil and an inner surface made of metalized PET with inside high-tensile spring steel wire

+ Product Details Size - 28"w X 18"h is the size for the duct opening measurement only

making it perfect for both residential and commercial installations

+ Product Details Size - 12"w X 36"h is the size for the duct opening measurement only

32" x 10" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w14h14 It has an outer surface+ Product Details Perfect Fit & Easy Sizing Designed for a 32" x 10" OR 10" x 32" duct opening (measured at the opening), with actual outer dimensions of 34. 5" W x 12. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 31. 75" x 9. 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