The E flat dominant ninth chord is a 5-note chord consisting of the notes Eb, G, Bb, Db and F.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Eb9.
Chords that are a superset of Eb9. The chords include more notes but always Eb, G, Bb, Db and F.
Chords that are a subset of Eb9. These contain less notes but all of them are included in Eb9.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Eb9 chord. Feel free to save or share the image as needed.