Original Brocade 57-1000027-02/57-1000027-01 XBR-000172 XBR-000153 SFP 8Gbase-LR 1310nm 10km Fibre Optic for Brocade 8510,DCX,6520,6510,6505,5300,5100,300, Encryption,7800,7840 Switch,optical transceivers are designed for 4.25Gb/s serial optical interfaces.Please read more on our web.