Rear Derailleur Model?

dude1 said:

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
Has anyone an idea?

The model number on SHIMANO rear derailleurs is typically stamped on the outside face of the inner parallelogram plate (you can view it through the rear wheel from the non-driveside of the bike ... accumulated grime may preclude being able to read it) ...

YOUR rear derailleur appears to be one of Shimano's TOURNEY rear derailleurs ...

While there is a huge difference in cost between the least & most expensive Shimano rear derailleur, all Shimano derailleurs (front & rear) will generally work well if they are properly maintained ...

RUST is the potential problem with an all-steel component ...

For the time being, lube anything on it which pivots with some 3-in-1 type oil ...

Ditto for the front derailleur's pivots.

Basically, you probably won't need to replace it unless you really want to spend the money on an ACERA-or-better Shimano rear derailleur.

Excellent.
According to the number, it's an Altus derailleur.
Thanks!