The surface of this kind of tube is smooth and the tube is colorless. The properties of the tube are: high purity(SiO2>99.99%),abrasion resistance(any acid except HF acid ).

Fire resistance(softening point 1700 centigrade). low coefficient of thermal expansion(5.5x10-7/centigrade,heat the tube to around 1100 centigrade,then put it into ordinary temperature water,the tube won't crack,); The surface can be done with gold plating.

Gently using sizes:
Single outer diameter X double outer diameter
8x17mm,11x23mm,15x33mm
Length 400-4000mm