... doesn't need any power, green and economic.4. Easy install, easy operation, fashionable.5. Well wind, snow and hail resistance.6. 72 ... Solar vacuum tube is pluged into the bottom of water tank, The water is filled inside the solar vacuum tube, Solar vacuum tube transmit solar ... steel or 0.4mm galvanized steel .3. Stand: galvanized steel with painting,or Aluminium alloy, or stainless steel.4. Water tank ...