{HEAD ~ A suitably insulated heating wire} 4 is carried by {TAIL ~ the tightening ring} 3 
is carried by
{ HEAD ~ A suitably insulated heating wire } 4 is carried by { TAIL ~ the tightening ring } 3
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH