The IC-8T-SW Mud Ring kit is designed to make the installation of our commercial ICSW-8T2 in-ceiling subwoofer easier and less time consuming when used in applications featuring a drywall ceiling. Constructed of durable, Zinc plated 20 guage steel these pre-construction brackets are suitable for use in plenum spaces. They attach to the ceiling joists ahead of the sheet rock installation and define where the loudspeaker through hole must be cut by the ceiling contractor. Part # 061347 is sold singly, packaged in individual cartons.