4" Round Return Air Vent Grille With Sponge Gasket And Mounting Frame - HVAC Vent Duct Register Cover [Outer Dimensions: 6"] w18h18 R value rating of insulation

R value rating of insulation - r3

[Outer Dimensions: 14

All of these grills have dampers

you have 16 different varieties to choose from

+ Product Details Size - 20"w X 8"h is the size for the duct opening measurement only

4" Round Return Air Vent Grille With Sponge Gasket And Mounting Frame - HVAC Vent Duct Register Cover [Outer Dimensions: 6"] w18h18 R value rating of insulation+ Product Details Size The listed 4" diameter refers specifically to the size of the duct opening. However, please note that the total outer dimensions of the grille measure 6" in diameter. Design Circular return 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. Mounted