The Model OTOLS-13, OTOLS-15 and OTOLS-CW small form pluggable (SFP) transceivers operate at 1.25Gb/s and are compatible with gigabit Ethernet and 1000BASE-T standards. The link uses a two-wire serial communication protocol based on current industry requirements. The compact metallic enclosure includes a standard LC connector and can be ordered for 1310nm, 1550nm, or CWDM transport. The transceiver may be used for bidirectional data links up to 1.25GB/s or switch-to-switch interfaces and router/server interfaces and can be ordered to operate up to 30km (1310nm), 80km, or 120km (1550nm) over single-mode fiber. The CWDM version allow up to eighteen (18) units to operate on one single-mode fiber. All SFP modules now include Digital Diagnostic Monitoring (DDM).