1) hard borosilicate tube 3.3 2)high efficient absorptive 3)triple target: SS-C/CU and AL/N 4)solar keymark.

Specification of solar vacuum  tube:

The marerial of glass tube: hard borosilicate :3.3

The thickness of inner and outer tube of:1.6mm

Absorption coefficient: more than 93%.

Absorptive coating :high efficient heat absorptive selective sputtering coating:

 SS-C/CU and AL-N/AL

Emission coefficient: less than 10%(8%)

Evacuated : less than  5*10-3pa

Stagnation temperature   220 degree Celsius

Hail resistance    25mm

Freezing resistance   -35 Celsius degrees

Tri-element solar vacuum tube