This product is the Non-Pressure Solar water heater. 
The material of this solar water heater:
Inner tank: SUS304-2B stainless steel, the thickness is 0.4mm; the diameter is 360mm;
Outer tank: 0.4mm thickness color steel plate or aluminum-zinc alloy steel plate, the diameter is 470mm;
Thermal insulation level: 55mm thickness imported polyurethane overall foaming;
Bracket: high aluminum zinc alloy steel plate with superior quality crook to forming, electric static spraying, economy and durability, or stainless steel SUS430-1.55mm, applicable to flat floor and pitched roof;
Vacuum tube:  all glass vacuum tube, two Pipes inlet-outlet type; the absorbing coating is used of QB-AL-N/AL-47-1500/58-1800.
Reserve the electrical heating gate and the gas vent,
There are other color for the bracket and ending cover: Derby red, dark green and saffron yellow.