air hose

The fresh air inlet hose to the heater box has self destructed (really!!)
during removal.  It has accordian sections of pipe at each end and "straight
pipe" (non accordian style) in the middle of the run.  It is all molded in
one piece.  I'm guessing it was original.  MossieBrit seems to offer  the
replacement as all accordian.  What was original?  If the piece I have
removed is the original style, who sells one like it?  Thanks, Larry