Help ID this Glass Sucking Creature

[RussWalters]

I have recently dropped live rock from TBS in my new tank and I have noticed two of these guys sliding up the glass on my tank. Any help on ID'ing them and letting me know if they are a nuisance or not. It seems like they have a bit of a hard outer shell, but I can't tell for sure.... I knocked one off the glass and it just headed right back there and re-attached itself.

Thanks in advance!

 

[jraker]

Looks like some kind of limpet.

 

[Ron Reefman]

Looks like some kind of limpet.

It's hard to say based on the photos, but I'd say you are right.

 

[Dogshowgrl]

Limpet. Good guy.

 

[SeaCucumberFan]

I'd say limpet

 

[RussWalters]

Thank you all. I think we can say case closed on this one. Limpet it is.