Tool question

I received the GMT as a Christmas present, and aside from being rather intimidated, I have a question about something included in the kit.
It’s a length of spring like wire with an anodized metal bulb on the end.
I can’t find any reference to it anywhere, and am hoping to find some clarification.

That’s for holding the loupe. It’s used when you want to go hand free with the loupe, so the metal wire goes around your head and the loupe goes into the ring side of it

Of course! Thank you, it’s obvious now.