Modular platform accepts a variety of lamp types and optical elements, Elements can be interchanged to create a variety of lighting effects, Plaster lip with direction marks accommodates ceilings 1/2 to 1" thick, Setscrews integral to bar hanger receivers provide positive locking, Bar hangers adjust up to 24" and have integral nail and tee grid clip, Junction box has (6) 1/2" pry-outs & suitable for (4) #12 thru-branch