This is a mini media converter that converts a 10/100Base-TX(RJ-45) to 100Base-FX(ST) via a 1310nm multi-mode fiber (MMF) ST connector, which allows distance reach up to 2km. This provides a cost effective conversion from 10/100Base-TX(RJ-45) to 100Base-FX fiber, while extending the network reach beyond the 100m reach limitation of copper and saving space (3.75" x 2.25" x 1"). Our media converters are 100% compliant for all of our networking needs. Now you have a cost effective solution to your network upgrade needs.