Cisco Dense Wavelength-Division Multiplexing (DWDM) 1556.55 nm SFP Module – 1 x 1000Base-X DWDM-SFP-5655=

AddOn QSFP28 Module – For Data Networking, Optical Network – 1 x LC 50GBase-BX Network – Optical Fiber – Single-mode – 50 Gigabit Ethernet – 50GBase-BX – Hot-pluggable – TAA Compliant Q28-50GP4-BXD3327-10-AO