We bought the wrong cards and I'm happy to give them away if you can use them.
They are for 24-hour passes for "2 Zone: Mi3 - Mi4". As far as I can tell, they are useful for going to the suburbs, not in the city itself.
Cost was 5.60EURO each. I don't know if they expire -- we bought them on/around 1/1/20.
If you can use them, I'll mail them to you. PM me.