The wire has a diameter of from about 0.1 to about 0.5 millimeters and is formed from platinum, {TAIL ~ iridium}, or {HEAD ~ a platinum/iridium alloy} 
The wire has a diameter of from about 0.1 to about 0.5 millimeters and is formed from platinum , { TAIL ~ iridium } , or { HEAD ~ a platinum / iridium alloy }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD