... Efficient heat-collection function: New generation o vacuum tubes, use molecular nanotechnology, enhance heat-absoration. ... gel.4.Vacuum tuber: High-efficient vacuum tube *High-Efficient heat-collection function: New generation of vacuum tubes, use ... ,heating automatically ,controlling automatically. Model:ModelLigthing(m2)Vacuum TubeSupply hotwater(L/D)20/40" containerdiameterlengthNo.IPYM420 ...