The tube has the following advantages: 1)Absorptivity:0.94-0.96 because of the copper insulation,the absorption of stainless steel and the decline heat of Aluminium layer. 2)Endure bad weather Our evacuated tube can endure temperature to 250。C，even under -50。C since the vacuum rate can reach less than 5.0×10-3pa. 3)Structure stability The tube prssure-endure ability can reach 1Mpa 4)Long life Patented conducting substance is compatible with normal metal material that result in non-condensable gas and non-stop running within 15 years and long duration for the collector. 5)Advanced technology Our company use 3 target magnetron sputtering plating technology,which introduce from Germany and also called interferometer coating technology. We have different diametical tubes, for example,47mm,58mm,70mm of external pipe.