1,quartz glass rod 2 tight tolearance 3,Resistance 1100 degree 4, no bubble no airline 5. non-discolouring ... convenient transportation access.Size: OD2mm-30mm1. purity : 99.99% min2. Resistance 1100 degree, 1000 long time work3. Low OH 4. Nice ... 70 speculations, ranging from 3-300mm clear quartz tube(high purity,good heating resistance,low OH), UV-stop quartz tube, red quartz ...