an inflator housing having two walls, an inner wall and an outer wall, {HEAD ~ the inner and outer walls} forming {TAIL ~ a combustion chamber} 
forming
an inflator housing having two walls , an inner wall and an outer wall , { HEAD ~ the inner and outer walls } forming { TAIL ~ a combustion chamber }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL