8" X 4" [Duct Opening] 1-Way Air Vent Adjustable Aluminum Curved Blades Integral Multi-Shutter Damper HVAC Diffuser [Outer Dimensions: 9.75"W X 5.75"H] w24h24 + Product Description Enhance your accordion content RFG2525 Black-HP 18" Round Duct Pipe

+ Product Description Enhance your HVAC system's efficiency and your home's aesthetics with our premium aluminum air vent diffuser

Actual Filter Size – 35 3/4"w x 27 3/4" x 1"

+ Product Details Size - 6"w X 28"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 30"h is the size for the duct opening measurement only

1-1/8" - 2334 PSI

8" X 4" [Duct Opening] 1 Way Air Vent Adjustable Aluminum Curved Blades Integral Multi Shutter Damper HVAC Diffuser [Outer Dimensions: 9.75"W X 5.75"H] w24h24 + Product Description Enhance your accordion content RFG2525 Black HP 18" Round Duct Pipe + Product Description Enhance your HVAC system's efficiency and your home's aesthetics with our premium aluminum air vent diffuser Actual Filter Size – 35 3 4"w x 27 3 4" x 1"