{HEAD ~ The end section} is non displaceable in its fully inserted position since the notch lies within the opening shaft of {TAIL ~ the flat sleeve} 
{ HEAD ~ The end section } is non displaceable in its fully inserted position since the notch lies within the opening shaft of { TAIL ~ the flat sleeve }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL