non pressurized outdoor compact Solar Water Heater

Inner tank and outer tank are both o point fourmm food grade stainless steel, welded by argon arc. Heat insulation of water tank adopts polyurethane foam, thickness is fifty-fivemm.
The tubes and supports are adjustable, power bearing is average and assure the tubes to use long time.
Whole vacuum tube adopts super borax and silica glass. Absorb rate≥ Ninety-three percent, thermal radiation rate≤ Six percent. Resist twenty-five mm hail, using life lasts fifteen years.
Silicon ring to connect and seal them.