{HEAD ~ The outer fins} 2 can be formed by making the material on the tube body 1 extend outward along radial direction of the tube body 1, and can be integrated with {TAIL ~ the tube body} 1 
{ HEAD ~ The outer fins } 2 can be formed by making the material on the tube body 1 extend outward along radial direction of the tube body 1 , and can be integrated with { TAIL ~ the tube body } 1
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH