... whole system guarantee 15 years vacuum tube guarantee * Water tank of 150L solar water heater, Outer tank material, Color ... , 15mm/20mm* Collector of 150L compact solar water heater Tube size58x1800mmOuter tube diameter58mmInner tank diameter47mmGlass thickness1.6mmMaterial3.3 high ... m2°C* Frame for 15 tubes vacuum tube type solar water heater Frame material, galvanized steel Frame thickness, ...