Abstract: A damper device for use with an air duct provides a paddle positioned within the duct and an axle extending distally from, and in a common plane with, the paddle through the duct wall, to a position for manual adjustment of the paddle within the duct. A bushing is tightened against the wall of the duct by a threaded knob and frictionally holds the axle in place using a combination of axially oriented fingers and O-rings. A handle is engaged with the end of the axle, enabling manual adjustment of the angular position of the paddle from outside the duct. The handle is in fixed alignment with the orientation of the paddle's peripheral edge, allowing for identification of the approximate angular position of the paddle from outside the duct, even when the duct is covered with a layer of insulation.

Abstract: A damper device for use with an air duct provides a paddle positioned within the air duct and an axle extending to one side of the paddle, through the duct wall and insulation to a position for manual adjustment of the position of the paddle within the duct. A bushing holds the axle in place, the bushing being tightened against the wall of the duct by a hand nut. The hand nut provides a brightly colored flag that is extendable when the damper device is in place. An O-ring is used to cause a frictional relationship between the paddle axle and the bushing so that the paddle is fixed into place once adjusted. A contour step on the bushing face allows engagement between the paddle and the bushing so as to hold the bushing from rotating while the hand nut is threaded into place on the bushing.