The corrigated vent has metal gaskets(?) where it attaches to the
frig ,proper. They are split. Kinda like half moons.u put two of them
together for the  vent,then screw on the big knureled knob.A big rubber 0
ring goes to aluminum end that exits the van.Several little parts ,total,
needed. Ebay  sometimes has these parts. Be aware that these corrogated
vents are fragile. If they are bent, they may crack a fine hair line crack
at the bend. Difficult to see this crack. The system will not be sealed
with this crack, and the frig gas pilot,will blow out on the road.The break
can occur when removing or installing the frig.Be careful.Better reseal the
3 utility boxes.