Cisco - SFP28 transceiver module - 25GbE - 25GBase-ER - LC single-mode - up to 40 km - 1295-1310 nm - for P/N: N540-ACC-SYS=, N540X-16Z4G8Q2C-A=, N540X-ACC-SYS=, NCS-55A2-MOD-HX-S