... : 1) high efficiency 2)reasonable price 3)ALN/AL-SS/CU Coating 4)Long life-span Glass Vacuum Tube :Certifactes: CE, ISO9001 ... /37mm; Φ58/47mm ; Φ70/58mm2.Length of Tube : 1500mm, 1800mm, 2000mm, 2100mm3.Material: Borosilicate glass 3.3 , Thickness of tube:1.6± 0.1mm,2.0 ... -elements coating ALN/ALN-SS/CU5.Thermal Expansion: 3.3*10-6/k6.Absorption of Selective Coating: α =90% -93% (AM1.5)7.Emission ...