This is clear fused quartz glass tube available as continuous machine drawn and automatic controlled tubing. It has the typical characteriastics of high purity ,good spectral transmission,well controlled dimension and lower OH.it serves as the first choice of heat resistant material for halogen lamps,mercury lamps,metal halide lamps and other quartz lamps.This glass can be supplied in the range of 3-80mm outside diameter,0.6-2.0mm wall thickness and 1200-1500mm length.Exhaust tubes with good CPK are suitable for high-speed streamline production .and further processing of trim cutting ,fire polishing ,bending and pinching can be done according to the requirement of customers .OH-content can be controlled within 20ppm15ppm5ppm2ppm according to the requirement of customers .