? Complies with IEEE 802.3 10Base-T, 802.3u 100Base-TX, 100Base-FX and 1000Base-Lx/Sx. ? Fiber connectivity up to 550m, 2Km for multi-mode and 120Km for single-mode ? Modularized design, all modules can be used in RCB Rack-mount model ? Utilizes WDM technology (models over 60Km for single-mode fiber cable) to provide TX and RX on a single fiber cable ? ST or SC connector. ? One RJ-45 for straight or cross-over connectio(using a DIP switch). ? Full-Duplex, Half-Duplex or Auto selectable ? 4 diagnostic LEDs VMC-10/100MC2 10/100Base,SX,MM,SC,2KM VMC-10/100SC30 10/100Base,FX, SM, SC, 30Km VMC-10/100SC50 10/100Base,FX, SM, SC, 50Km VMC-10/100SC100 10/100Base,FX, SM, SC, 100Km VMC-10/100SC120 10/100Base,FX, SM, SC, 120Km VMC-10/1000SC550 10/100/1000Base, SX,MM,SC,550m VMC-10/1000SC20 10/100/1000Base,LX, SM,SC,20KM VMC-10/1000SC50 10/100/1000Base,LX, SM,SC,50KM