With several trace elements added, the red quartz tube can stop UV and part of light, which can make full use of infrared ray. We have three colors for your choice .It is pink, wine red and dark red, all of which are transparent. The common outside diameter is between 6mm and 19mm. Red quartz tubes are used in the field of far infrared heating, such as heaters, sterilization tanks, microwave ovens, electric cookers, electric stoves, surface drying, automobile paint baking, etc.