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.
Interactive piano diagram for the E flat dominant flat ninth chord
Chords that are a subset of Eb7b9. These contain less notes but all of them are included in Eb7b9.