Helmet's mirror up/down? or (closed/open)?

[Scofield]

When I am wearing a helmet how we express it's mirror is up/down? or (closed/open)?

Example: You should wear the helmet with it's mirror down to help protect you from dirt.
Is it right?

[Josef Essberger]

When I am wearing a helmet how we express it's mirror is up/down? or (closed/open)?

Example: You should wear the helmet with it's mirror down to help protect you from dirt.
Is it right?

I think it's a visor not a mirror, and you would say:

- You should wear the helmet with its visor down to help protect you from dirt.
- You should wear the helmet with its visor down to shield your eyes.
etc

Notice "its" not "it's" (which means "it is").