Model:EW-SFP-FE-SD1310 100M , Accessory 155M Single-mode Dual Fiber SFP Module 1310nm 20KM (EW-SFP-FE-SD1310) Model:EW-SFP-FE-MD850 100M , Accessory 155M Multi-mode Dual Fiber SFP Module 850nm 550meter