14" x 16" or 16" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Round Duct Pipe It features an eight-tumbler lock

It features an eight-tumbler lock with a supplied key for secure access

75"H – fits a 12" X 4" duct opening

75"H – fits a 18" X 4" duct opening

Filter Size - 23

14" x 16" or 16" x 14" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 6" Round Duct Pipe It features an eight-tumbler lock+ Product Details Perfect Fit & Easy Sizing Designed for a 14" x 16" OR 16" X 14" duct opening (measured at the opening), with actual outer dimensions of 16. 5" W x 18. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 13. 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