These roof flashings go around the exterior intake pipe in the Sterling concentric vent kits to keep out rain and snow and provide a finished look.
The 7" models are for the 4" concentric kits.
The 9" models are for the 5" concentric kits.
The standard pitch flashings are for roofs with 1/12 to 6/12 pitch.
The steep pitch flashings are for roofs with 7/12 to 12/12 pitch.