The Chief CMS390 On-Center Ceiling Plate is designed for use in a ceiling mounted projector installation. It serves as the base of the hardware used to suspend the projector from the ceiling. This plate is designed for installation between 16" on-center joists. Simply attach the plate to the ceiling using the included lag bolts. The plate features a threaded fitting that will accept a 1.5" NPT threaded extension column, from which you can hang your projector. The plate can also be used on structural ceilings using concrete anchors.