The E flat dominant flat ninth chord is a 5-note chord consisting of the notes Eb, G, Bb, Db and Fb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Eb7b9.
Chords that are a subset of Eb7b9. These contain less notes but all of them are included in Eb7b9.
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 Eb7b9 chord. Feel free to save or share the image as needed.