This derailleur will work on a 3x9 , 2x9 , or even a 2x10 drivetrain.
Derailleur is in excellent condition, and fully functional when removed (still nice and stiff precise movement). I'd put a excellent lube (tri-flow or Boshield) on derailleur pivots 1-2 times per year , and do a fine detail clean once per year. After each ride , I'd whip down dirt /debris. This component was used 1-2 rides per week (weekend warrior riding ....not several times per week , and not racing).
I'll package derailleur snug in a large enough box for safe delivery.