... structure,easy installation. 3.Outsta non-pressure solar water heater:1.Vacuum Tube Specifications:Dia 47x1.6,Dia58x1.8,Dia58x2.12 ... .Water Tank Liner: Imported SUS304-2B food ... pressure run4.Tank shell:Brushed silver porcelain plate5.Tube Number Range:16,18,20,24,30,366 ... , simple structure,easy installation non-pressure solar water heater