King of the Road tube to where?

[dmascheck]

I have a 2006 King of the Road Royal Villa. Noticed over the dining room slide a pvc tube that is capped. Can't find anyone that has an idea what its for. It has to go through the roof?

For some odd reason it turned the picture sideways. The tube goes up like through the ceiling!

HELP!

[CHAPS2018]

Is it a cable pass-through port? Ie, for ham antenna, satellite, solar?

How does it look topside? Sealed? Does the cap come off on either top or bottom?

[dmascheck]

Hate to say it, but it came loose and is a carbon dioxide/smoke detector.