Bambi exposed plumbing

[skipj]

I'm looking at 19 foot Bambi trailers. On one of the dealers sites, there is a photo of the underside of a 2012 unit which shows 2 lines coming out of the bottom of the trailer and running to a third line which runs front to back. I saw another underside shot of a airstream with four lines exiting the under pan and running over to the side. Look like colored plastic. Does anyone know what they are. Look like the could easily be pulled off.
Thank for any help in advance.
SkipJ

[TBRich]

I just looked under our 2006 19' foot...the only lines exposed on the outside of the belly pan are gas lines...and in the rear curbside quarter (behind the axle) the gas line to the water heater and fridge is a copper line is inside of a plastic tube, presumabley to act as sheathing to protect the gas line. Gas lines are typically run on the outside because they are safer there in the event a leak should develop. The only color lines I am aware of are red (hot) and white (cold) water...and those are all interior, of course.

[skipj]

Just wondering if they do that on all of the Airstreams?