18"W X 18"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 19.875"W X 19.875"H] 8in diameter actual front end outer dimensions

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

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings

Its smooth

actual front end outer dimensions are approximately 18 5/8" width X 16 5/8" height

18"W X 18"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 19.875"W X 19.875"H] 8in diameter actual front end outer dimensions+ Product Details Size 18"w X 18"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 875" width X 19. 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