... it has a good anti-emergency heat, solar vacuum tube ItermsSizeCapacity(L)Absorb area(m2)20GP/40GP loading ... qty(pc)single vacuum tube47*12001.290.074200 / 896047*14501.560.083360 ... ratio: ξh=0.04-0.06(80`±5)Vacuum tightness: P≤5.0*10-3PaPackage: cartonOur company ... ,Haining Aoxin Solar Collector Tube Co.,Ltd , is a manufacturer of solar ...