Optical Fiber Modem (FOM) is a device which is used in optical fiber networks for sending and receiving data. Fiberinthebox optical fiber modems are available in various form factors depending upon the protocol selected, such as RS-232/RS-485/RS-422 Optical Fiber Modem. Our FOM has a higher bandwidth and greater electromagnetic immunity than wire-based modems. Together with multimode or single-mode fiber, the optical fiber modem allows data to be transmitted and convert electrical signals to light. It provides transmission distance up to 2km (multimode) or up to 20km/40km/60km (single-mode).