... loss, quick temp. rising, reliable quality, 5years war Three high Vacuum Solar Collector - solar vacuum tube has property and spec. as following:Spec.1. ... )/ALN 4. Sediment method: 3 target magnertron sputtering platingComparing to Al-N-Al vacuum tube, it has advantages in cold area ... performance of high temp. resistant, anti-stagnation temp. coating will not decay or get aging or disappears.Size:Dia ...