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