The U type series solar water heater,module design, arbitrary combination, can be put on the inclined roof or ... with the building perfectly; 3.Intelligent control and automatic operation; 4.Anti-freeze: No water inside the tubes when it works. 5 ... ) Tube standards: 15, 18,30,36,45tubes with 58mm diameter and 1.8m length solar water heater (split design, bear the pressure)