The conductor can be surrounded by {TAIL ~ additional layers} of polymeric material as long as the outer layer comprises {HEAD ~ the first polymeric material} 
The conductor can be surrounded by { TAIL ~ additional layers } of polymeric material as long as the outer layer comprises { HEAD ~ the first polymeric material }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD