characters:

1.can be used for pressure solar collector or compact pressure solar water heater.

2. it can bear 6 bar pressure.

3. there is heat pipe and aluminium ring in each vacuum tube,and with silicon rubber to seal it.heat pipe will transfer heat energy

4.there isn't any water inside the vacuum tube,so when the user use solar water heater,if one vacuum tube is broken,it will not effect the whole machine,the solar water heater can still work without water leakage.

5.good quality heat pipes.The heat efficiency of vacuum tube is high,more than 90% absorption rate.