The E flat fifth chord is a 2-note chord consisting of the notes Eb and Bb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Eb5.
Chords that are a superset of Eb5. The chords include more notes but always Eb and Bb.
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 Eb5 chord. Feel free to save or share the image as needed.