I have many teeth that easily break, as I chew through knots that frustrate. Cool guys keep me on hand, or in back pocket rather than.

I go up, it's bright, I go down, it's dark. I do this so fast you don't even notice Looking for rapid moves right below me? In your dreams! I protect, I shimmer, I'm glamorous. I come in different shapes and sizes.

56, 57, 7, 58 Equilibrium achieved. I am in what state?

I sit around the castle, and make reaching the front door inconvenient.

What five letter word remains the same if you remove the first, third, and fifth letter?