30" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w30h30 + Product Details Size –

+ Product Details Size – 26" x 34" or 34" x 26" is the size for the duct opening measurement only

Built-In Locking System – Comes with a permanently attached eight-tumbler lock and a supplied key for added security

+ Product Details Size – 18" x 32" or 32" x 18" is the size for the duct opening measurement only

+ Product Details Size - 4"w X 20"h is the size for the duct opening measurement only

30" x 12" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w30h30 + Product Details Size –+ Product Details Perfect Fit & Easy Sizing Designed for a 30" x 12" OR 12" x 30" duct opening (measured at the opening), with actual outer dimensions of 32. 5" W x 14. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 29. 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