Categoryï¼� Single- target vacuum tubesã�� Tri-element Hitech vacuum tubes ã�� Three- target tubes External pipe diameter and thicknessï¼� �¦=47�±0.7mm &=1.6mm �¦=58�±0.7mm &=1.6mm �¦=70�±0.7mm &=1.6mm Internal pipe diameter and thicknessï¼� �¦=37�±0.7mm &=1.6mm �¦=47�±0.7mm &=1.6mm �¦=58�±0.7mm &=1.6mm Sediment methodï¼� Single target magnetron sputtering plating Three target magnetron sputtering plating Three target magnetron sputtering plating Specific absorptionï¼� a=0.90~0.93 (AM1.5)a=0.93-0.96(AM1.5ï¼�ï½�=0.92~0.96(AM1.5) Emission ratioï¼� �µ=0.05~0.075(80�°C�±5�°C) �µ=0.04~0.06(80�°C�±5�°C) �µ=0.04~0.06(80�°C�±5�°C) Vacuum tightness ï¼�Pâ�¤5.0��10-3 Pa Average heat loss coefficientï¼� U=0.6~0.7W/(m�².�°C)U<=0.6 W/(m�².�°C) U=0.4~0.6W/(m�².�°C) Packaging Carton Routine Packaging:8 or 10 or 12 pc /carton Special Packaging: According to what customs need