ADD-RS232-2ST is a Serial Media Converter that allows the conversion from a RS232 Port to Fiber via a 1310nm single-mode fiber (SMF) ST connector, allowing a distance reach up to 20km. ADD-RS232-2ST provides a cost effective conversion from Serial RS232 to Fiber, while extending your network reach beyond the 100m reach limitation of copper.Addoncomputer.com Media Converters and Network Interface Cards are 100% compliant for all of our networking needs. Now you have a cost effective solution to your network upgrade needs. With our ADDON CERTIFICATION TEST Program, we can guarantee your product will work right the first time.