{HEAD ~ The axle unit} 20 is located within {TAIL ~ the two flanges} 13 and the hollow tube 14 
is located within
{ HEAD ~ The axle unit } 20 is located within { TAIL ~ the two flanges } 13 and the hollow tube 14
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH