Guzzi Strada 1994 fuel tap sender

Does anyone know how the left hand fuel tap electrical reserve float works. Removed tap and sender but how on earth does the black rubber type float make a connection with the wires coming out of the tap to the fuel light indicator on the dash. And why is the float at the top of the brass rod and not the bottom. Just baffled how the conections work.

Just guessing, but it might be a magnet and reed switch type of thing. I also suspect it’s at the top of the rod because it’s stuck(?) Supposed to slide?

It slides ok It might be a broken wire inside the rod, if there is one inside !
Has I have said (thanks for your thoughts) but does anyone know exactly how it works