At least a portion of {HEAD ~ the member} is in {TAIL ~ thermal contact} with the opening and is made of a material reactive with electromagnetic energy 
At least a portion of { HEAD ~ the member } is in { TAIL ~ thermal contact } with the opening and is made of a material reactive with electromagnetic energy
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH