{TAIL ~ A thermal resistor} can be provided between {HEAD ~ the outer fin} 2 and the tube body 1 
{ TAIL ~ A thermal resistor } can be provided between { HEAD ~ the outer fin } 2 and the tube body 1
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH