The E flat dominant seventh chord is a 4-note chord consisting of the notes Eb, G, Bb and Db.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Eb7.
Chords that are a superset of Eb7. The chords include more notes but always Eb, G, Bb and Db.
Chords that are a subset of Eb7. These contain less notes but all of them are included in Eb7.
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 Eb7 chord. Feel free to save or share the image as needed.