MacBook - anodized or bare aluminum?

Question

macbook

MacBook Pro 13" retina late 2013 - bare aluminum surface or anodized aluminum? If anodized, then with what?
// The manufacturer put a bronze snake in the bag, I think whether to change it to plastic or not. If it is anodized with something with a microhardness higher than that of bronze , then I will not change it.Now it strains the sound of shuffling when pulling out the laptop from the bag.

Answer 1

To change it, it costs us 30-60 rubles.
There's no point in even thinking about it.