This fixture has a range of motion which allows it to be adjusted so the two sets of shades can be positioned in one straight line 173 inches long by 33 inches wide; or turned up to 90 degress forming a 124 long by 74" wide pattern. It was built with two thrust bearings on each swing arm for smooth operation. It also has ball plungers with detents for stopping in two positions. It has mechanical stops to keep it from over rotating its range."