What is this sender??

Just stripping '75 1800 Kombi motor and came across this sender, never seen one before and some soul has cut it's wire. Any idea of what it is for?

THanks

Other side of sender

Thats a hard one...
looks like a magnetic pick up...
the other bit would be in the flywheel....

strange.... is it for a tacho???
was it something to do with a 4 wheel drive set-up
with VWs synchro transmission??

I'm guessing here !!!!🙂🙂

Lee

diagnostic pickup????

I was guessing FI pickup??

i remeber being told what it was, but cant recall now, ages ago
my 1600 had it, but it wasnt hooked up