になります for being polite

When I first learned about になる it was about “to become” like

医者になります。
Become a doctor.

But today I saw this sentence:

中古品として購入したものになります。
It was purchased as a second-hand item.

So I tried searching Noun + なります without much luck until I found:

What does ものになります mean?

So it’s just a polite way for noun + です. It is often used by store clerks.

Instead of saying: コーヒーです。
They’ll say: コーヒーになります。
Here’s your coffee.