... : 1.Solar water heater with CE,CCC,ISO9001,CNAL certificate2.Special high quality Insulated material to reducing the heat loss rate ... 50mmVacuum tube: AL/N coating, 47*1500/58*1800mmAccessories: MG rod, electrical heating, assistant tankLogo: OEM, co lour printing / ... sunshine. The cold water in water tank flows into the tube and become hot, because of different density between cold and hot water, there ...