Roof Jacks & Extensions.
Nordyne/Miller/Intertherm CMF Roof Jack 4in Pipe 28in (FM-103947002)
This roof jack pipe connects furnaces to roof jacks. The roof jack should be installed so it extends below the ceiling; the pipe then slides inside the roof jack and connects to the furnace. Length is adjustable based on how far the pipe slides inside the roof jack.
Note: This pipe can only be used with SRJ series roof jacks.