1.Pre-heated solar water heater(CE, CCC) 2.compact solar water heater 3.8KGS copper coil inside water tank Pre-heated solar water heater (pressurized solar water heater with copper coil),the characteristic of pressurized solar water heater with copper ... grade Stainless steel, thcinkness:0.31mm. 2) Vacuum tube: 58mmx1800mm, High borosilicate glass, vacuum tubes, 3) Outer tank: Pearly steel plate ...