One plugs it into one's camera, in between the camera and recorder, and the device converts / outputs whatever transmission type you need for the recorder.
Why do you think the switch is a converter? Can you buy it stand alone?
If it is a dongle converter I am definitely impressed; I abandoned the idea, (with j.d.'s encouragement), a while back here, Can You Create A TVI To CVI Adapter?.
Did the major Analog provider state it was an inline converter? My thought was that was just a switch to the camera to change the output type to the dvr.
Since you may not be able to reach the OSD initially, depending on which kind of recorder you are using, they needed an external way to switch the output format of the camera.
Of course, a 5 way analog converter the size of a key fob is way cooler, so I'm hoping you are right!