Always circling around the sphere. Seeing all, have no fear. Relaying messages for your communication gear.

A block in the back, A sealer of a snack, Or something that holds ammo for an attack.

Some like to see me go up, whereas others like to see me go down. I like to be stepped on, yet I never complain, Sometimes I’m slippery, sometimes a bit plain. I’ll shimmer if you guess what I am.

I have a spine, but no bones; a face and a back, but no head.

Round and round in cars and clocks, I grab with my teeth and turn in my box. Big pushes small around smaller pin. Some call me simple, but all need my spin.