28" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades with Damper + Product Details Outer dimensions:

+ Product Details Outer dimensions: 13

Crafted for durability and rust-resistance

actual front end outer dimensions are approximately 22 5/8" width X 10 5/8" height

Ideal for Walls & Ceilings: Designed for seamless installation in standard 14" X 8" duct openings

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

28" x 36" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Fixed Blades with Damper + Product Details Outer dimensions:+ Product Details Perfect Fit & Easy Sizing Designed for a 28" x 36" OR 36" x 28" duct opening (measured at the opening), with actual outer dimensions of 30. 5" W x 38. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 27. 75" x 35. 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