18"W X 36"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 19.875"W X 37.875"H] Compatible With Duct 6in It has an outer surface

It has an outer surface made of high-quality aluminum foil and an inner surface made of metalized PET with inside high-tensile spring steel wire

All of these grills have dampers

Cubic core eggcrate design has the highest rate of airflow efficiency

+ Product Details Size – 30" x 34" or 34" x 30" is the size for the duct opening measurement only

Choose our premium HVAC grilles and registers for long-lasting durability

18"W X 36"H [Duct Opening] ALUMINUM RETURN GRILLE - EASY AIR FLOW - LINEAR BAR GRILLES [OUTER DIMENSIONS: 19.875"W X 37.875"H] Compatible With Duct 6in It has an outer surface+ Product Details Size 18"w X 36"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 19. 875" width X 37. 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