Strange slow moving stony worms. need an ID

[Kinko]

saw one of these in the day but at night caught alot of them, removed 1 but barely moved when touched

 

[Tuan’s Reef]

These? Does it have a shell? Or more like a flatworm?

 

[Tuan’s Reef]

Maybe limpets or chitons if shell

 

[19Mateo83]

Looks like chitons.

 

[Sisterlimonpot]

I'll agree, they're chitons

 

[Kinko]

ahh thank you all, now I feel bad for killing the one of them some weeks ago thinking it was a parasite >.>
I'm guessing they're reef cleaners?

 

[Tuan’s Reef]

Yep, they are good cuc members. Algae eaters