1,quartz heating rod: 2 purity 99.99% min 3,Resistance 1100 degree, 1000 long time work 4, nonbrowning no blackline non-discolouring No black quartz heating rod1, quartz heating rod : 2 purity 99.99% min3,Resistance 1100 degree, 1000 long time work4,Low OH5, no bubble, no airlineSpecification:Outer Diameter: 2-40mmAdvantage of the quartz tube:1. High temperature resistant, 1100 degree.2. ...