The lesson with the nuts

There is a lesson to be learned with the nuts: alloy wheels need specific nuts and steel wheels need a different type of nuts. At first look they are similar, but they are still different and can not be used on different type of wheels.
We have first fitted the steel winter wheels with the alloy nuts, took some photos but in a few moments later bought new nuts for steel wheels. And there is a difference which can be seen from the photos, not mentioning the safety.
The new nuts:

The steel wheels with the alloy nuts:

And the steel wheels with the steel nuts: