{HEAD ~ A spring} on the other end of the collette presses the collette against the shell to produce {TAIL ~ wiping contacts} at the opening 
{ HEAD ~ A spring } on the other end of the collette presses the collette against the shell to produce { TAIL ~ wiping contacts } at the opening
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH