25G LWDM SFP28 is an optical transceiver that transmits a 25 Gbps signal using Lan Wavelength Division Multiplexing (LWDM) technology. The primary purpose of this module is for use in LWDM multiplexing systems. In such a system, multiple 25G LWDM SFP28 transceivers, each tuned to a different channel within the LWDM grid, can have their signals combined over a single pair of fibers.