... RS485 Data 3 Levels Lightning Proof, Dual Powe 2CH Video Optical Transceiver Support Max. 20CH 232/485/CAN cable, 16CH Audio, 16CH ... special note, are 10bit, 20KM distance,single mode FC fiber connector, single fiber bi-directional transmission.6, RS232, RS485,RS422, etc Supportable Optical Transceiver