... .Assured quality,fast deliverystainless solar water heater,solar water heater ,solar energy,renewable stainles vacuum tube solar water heatersWorking principle:1) The split pressurized solar water heater composed of solar collector, storage tank, controller ... . Collector crust: Aluminum alloy 3. Tube with 58mm dim, 1.8m length 4. Water capacity: 150L / 200L / 300L(according to customer's request ...