What is this key type thingy?

[lakster]

Any idea what this is for, in glovebox of c180 w202

Tia

 

[Spider10]

That is an aftermarket immobiliser key there should be a slot to put it in if it's for that car

 

[lakster]

That is an aftermarket immobiliser key there should be a slot to put it in if it's for that car

Thanks @Spider10
There is a slot in the back of the glovebox which fits.
So if left in it will immobilize?

 

[Spider10]

If left in it will start if taken out it won't or shouldn't