30" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w20h20 Ideal for Walls & Ceilings: Suitable for all AC 8in diameter 12125SDCLNGBX

Ideal for Walls & Ceilings: Designed for seamless installation in standard 10" X 10" duct openings

actual front end outer dimensions are approximately 10 5/8" width X 30 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 34" OR 34" x 36" duct opening (measured at the opening)

actual front end outer dimensions are approximately 27 5/8" width X 20 5/8" height

30" x 6" Cube Core Eggcrate Return Air Filter Grille for 1" Filter w20h20 Ideal for Walls & Ceilings: Suitable for all AC 8in diameter 12125SDCLNGBX Ideal for Walls & Ceilings: Designed for seamless installation in standard 10" X 10" duct openings actual front end outer dimensions are approximately 10 5 8" width X 30 5 8" height