Your looking at a used SRAM Rival 10 speed rear derailleur.  The derailleur is in good shape.  It shows a little bit of road rash and what looks like a bit of rack burn, but functions just fine.  How ever both pulleys are cracked (see photos).  I don't think I saw any SRAM derailleurs from this generation, either road or mountain, that didn't crack the pulleys.  Replacements are pretty easy to find.

Thanks for taking a look and feel free to message me with any questions.