{TAIL ~ The assembly} 1, wherein the casing and the collars are made of {HEAD ~ composite material} 
{ TAIL ~ The assembly } 1 , wherein the casing and the collars are made of { HEAD ~ composite material }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD