Derailleur model

[dude]

Just bought a used MTB with several XT components and some lower quality ones.
I can't figure out the model of the rear derailleur
It's Shimano, but I don't know which one
https://drive.google.com/file/d/0By-S838OebDHOEVuZFpWdm9uNHM/view?usp=sharing
Has anyone an idea?
Thanks

[nfmisso]

I know, not very helpful - it is not XT, is low end, maybe not bottom of the line, but one up.

[dude]

I found it with the number, it's an Altus.
Thanks anyway.