Vacuum tubes assimilate the advanced 12 years of spattering deposition of trivalent element technology, high borosilicate glass, gradual
change of CU – AL – N / SS selective complex absorptive coating. And these make vacuum tubes having high performance of absorptance
and low reflection ratio. Through the interlayer, vacuum has a unique effect of thermo, with its temperature up to 380° C of idle sunning,
performing a strong heating ability.