The outside diameter is greater than 60mm. Its silicon dioxide content is more than 99.98%. The total content of Fe, Al, Ca, Mg, K, Na, Ti, Li, Cu, B, Cr is less than 45ppm. This kind of product has excellent physical and chemical properties, such as heat stability, electrical insulation, light transmittance and corrosion resisting. It is widely used in the high-technology fields, like semiconductor technology, integrated circuit production, optical fiber telecom, laser technology, space flight technology, national defense and military industry, and optical industry etc. Besides, it also can be used to make quartz apparatus and quartz plate.