12"W X 4"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 13.875"W X 5.875"H] Supply Grille + Product Details Size -

+ Product Details Size - 10"w X 4"h is the size for the duct opening measurement only

Optional Butterfly Damper Available At Asin: B007CNEL1W

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

The process is intuitive: simply select the appropriate ceiling square for your grill

12"W X 4"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 13.875"W X 5.875"H] Supply Grille + Product Details Size -+ Product Details Size 12"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 875" width X 5. 875" height. High Quality High quality aluminum with counter sunk screw holes (screws included) and no sharp edges. Design Unrestricted airflow For Your HVAC system noise free components no vibrating louvers etc. Powder Coat Finish Smooth, shiny, scratch resistant, beautiful. Looks like it was