10"W X 10"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 11.875"W X 11.875"H] 18in diameter + Product Details Size –

+ Product Details Size – 24"w X 24"h is the size for the duct opening measurement only

Energy Efficient – Air-tight inner core decreases the pressure loss and provides a more hygienic environment - high energy efficient / No fiberglass erosion into air stream

+ Product Details Size – 8"w X 6"h is the size for the duct opening measurement only

+ Product Details Size - 25"w X 20"h is the size for the duct opening measurement only

The first number in a grille size

10"W X 10"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 11.875"W X 11.875"H] 18in diameter + Product Details Size –+ Product Details Size 10"w X 10"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 11. 875" width X 11. 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