This is a mini media converter that converts a 10/100Base-TX(RJ-45) to 100Base-SX(ST) via a 850nm multi-mode fiber (MMF) ST connector, which allows distance reach up to 550m. This provides a cost effective conversion from 10/100Base-TX(RJ-45) to 100Base-SX fiber, while extending the network reach beyond the 100m reach limitation of copper. Our media converters are 100% compliant for all of our networking needs. Now you have a cost effective solution to your network upgrade needs.