Micks just got one, and it was either Foggy's or Adams who was FI to start with (Adams I think, but Foggy has a sender anyway)
The thing really isn't high tech, old skool analogue, like the FI system itself

Copies really don't look to be difficult, but there always something ready to bite you on the arse

I need a similar thing for when I convert my 400 info centre to FI engine (and I don't want to have to use the orig 400 software on it, but thats another project)