{HEAD ~ the annular shoulder} is centered at {TAIL ~ an axial distance} from the front end of the tip substantially equal to one half said axial distance of the center of the waist 
is centered at
{ HEAD ~ the annular shoulder } is centered at { TAIL ~ an axial distance } from the front end of the tip substantially equal to one half said axial distance of the center of the waist
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH