The UA-152-IC-SST is a single stereo “drywall speaker” that is installed flush into the plasterboard ceiling and/or wall. The front is made of plasterboard; the fine filling work on the frame, in which the grille sits flush, has already been completed at the factory. A big advantage is that the drywaller does not have to deal with complex, detailed work on the construction site. The transitions between frame and grille are absolutely clean.