Say you have a Single Mode fiber install coming into a facility. You then take that fiber connection and use a media converter to translate it out to Ethernet. That Ethernet connection then sends it out across a Multimode fiber run of any given length and is then converted back to an Ethernet hand off.
Does it work?
Example:
ISP delivers service via Single Mode, but outputs via Ethernet. That ethernet feeds to a multimode fiber converter box which transmits it across a facility to another media converter which translates it back to Ethernet to be input into whatever device on the other end.
TL;DR:
ISP delivers Ethernet -> Converter -> Multimode Fiber - Converter -> Ethernet -> Router/Gateway -> Network
