آداپتور دوبلکس  تولیدکنندگان، عرضه‌کنندگان، توزیع‌کنندگان

GRT(Beijing Guangruntong Technology Development Co., Ltd.) is headquartered in Beijing Zhongguancun Hi-Tech Park and began in April 2008. GRT has gathered a group of senior R&D personnel with an average age of more than 15 years. Under the background of the rapid development of the optical fiber industry and the optical fiber to households, GRT has always adhered to the strategic principles of quality and innovation, and has gradually grown into a high-tech fiber optic company that is currently well-known in China, which integrates R&D, production and marketing, and has its own intellectual property and its own brand.
The main products of GRT are Optical Fiber Network Cards, Optical Fiber Modules, WDM devices, Optical Converter, Optical Fiber Patch Cord, and Optical Splitter. All kinds of products have passed international certification such as FCC, CE, and ROHS, as well as national industry certification, and have won a number of scientific and technological progress awards and excellent product awards. On the road ahead, GRT is committed to building China's own national enterprises, achieving the goals of "Optics Links The World, Connects Us Togetcher".

As family-owned company the Telegärtner Group has developed to an international network of affiliated companies specialising in intermediate and end products for telecommunications and data communications for customers with the most exacting demands for high-tech applications over the last 70 years.