One of {TAIL ~ the first and second stacks} of {HEAD ~ folded portions} of the air bag is disposed in the upper chamber portion 
One of { TAIL ~ the first and second stacks } of { HEAD ~ folded portions } of the air bag is disposed in the upper chamber portion
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH