6" Round Air Vent Supply Grille With Sponge Gasket And Mounting Frame - HVAC Vent Duct Register Cover [Outer Dimensions: 8"] Brown + Product Details Size -

+ Product Details Size - 18"w X 22"h is the size for the duct opening measurement only

Actual Filter Size – 25 3/4"w x 11 3/4" x 1"

lightweight aluminum

actual front end outer dimensions are 21

6" Round Air Vent Supply Grille With Sponge Gasket And Mounting Frame - HVAC Vent Duct Register Cover [Outer Dimensions: 8"] Brown + Product Details Size -+ Product Details Size The listed 6" diameter refers specifically to the size of the duct opening. However, please note that the total outer dimensions of the grille measure 8" in diameter. Design Circular air supply valves designed to be used in low and medium pressure ventilation air conditioning systems, of up to 300m3 h. Adjustable airflow control by rotating the middle disk, the gap will expand and retract to meet perfect air supply needed.