All Enforcer ceiling speaker assemblies, round and square, are assembled at our facility using the parts listed in this catalogue. These assemblies are available in several configurations, from a standard 4 hole torsion mount, with and without volume control. They come complete with speaker & transformer mounted to the baffle and is ready to be installed. For specifications on speakers please refer to pages click here . Speaker assemblies that are going to be installed in drop tile ceilings require T-Bar supports ( click here )