The first metallic electrode comprises copper or an alloy of {TAIL ~ nickel} and {HEAD ~ copper} 
The first metallic electrode comprises copper or an alloy of { TAIL ~ nickel } and { HEAD ~ copper }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD