If you have a Forsaire Top-Vent heater recessed in an interior wall that is adjacent to another room, then you can now add heat to that room! With the installation of a rear outlet register, the warm air can be directed to this second room. The finished wall cannot be more than 3/4 inches from rear of the furnace. The built-in damper allows you to control the air-flow to the second room. The rear outlet kit includes the rear-outlet register, 1" boot and a damper.