Abstract: A damper assembly constructed of plastic for controlling airflow through a duct, wherein the blades are mounted for rotation between open and closed positions. The damper assembly includes a frame which is integrally formed with a louvered register and has a pair of spaced frame members with blade mounting portions defined therein in aligned cooperating pairs. The blade mounting portions are constructed to form a snap-in mounting for each of a series of generally rectangular blades having an axis of rotation, defined by journals at the ends of each blade, extending longitudinally and substantially centrally of the blade. The blades are operatively interconnected by intermeshing gears to be simultaneously rotated between the open and closed positions.