ID please

[i like fish]

Is this some kind of flatworm? It looks like it's armored, like an armadillo kinda.
I've seen a couple, always on the rock, and they move very slowly.
Is it harmful?
Pic below.........

 

[i like fish]

 

[sammystingray]

Chiton perhaps? The pic is kind of blurry.

 

[i like fish]

I just looked up chitons, that's what it is all right. It sounds like they are safe, just grazers.
Thanks Sammy!