glc-lx-sm SFP transceiver 1550NM 70KM LC GLC-SX-MM 850nm cisco,3com compatiable glc module GLC-LX-SM 1310nm single mode LC sfp glc-lx-sm SFP transceiver 1550NM 70KM LCglc-lx-sm SFP transceiverGLC-SX-MM 850nm cisco,3com compatiable glc moduleGLC-LX-SM 1310nm single mode LC sfp sfp moduleGLC-LX-ZX 1550nm 70km module 155M,1.25G,2.5G,4.25G SFP transceiver