Cisco - XENPAK transceiver module - 10 GigE - 10GBase-LR - SC - up to 6.2 miles - 1310 nm - refurbished - for P/N: 4-10GE/ 4-10GE=/ WS-X6704-10GE/ WS-X6704-10GE=/ WS-X6704-10GE-RF