Features 3 target sputtering plating Structure: all glass double-tube coaxial structure Material: high borosilicate glass 3.3 Interferential coating: Cu/Ss-ALN/ALN compound absorb coating Capabilities: Fast thermal collecting efficiency High heat resistance Super cold resistance Specific absorption: As= 0.93-0.96(AM1.5) Average heat loss coefficient: 0.4-0.6W/m²oC