Help getting started with OneTouch

I bought a one touch from ebay without instructions, and I just wanted to get a few things straight before I start using it.

I know that you need to insert the needle in to the foctile before touching the metal band with your finger.

But there are 2 metals bands. There’s one on the stylus and one on the device itself. Which one do I use?

Can I use either one? Or do I need to use both at the same time?

EDIT: Nevermind, I figured out that both work.