The E flat minor/major seventh chord is a 4-note chord consisting of the notes Eb, Gb, Bb and D.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Ebm/ma7.
Chords that are a superset of Ebm/ma7. The chords include more notes but always Eb, Gb, Bb and D.
Chords that are a subset of Ebm/ma7. These contain less notes but all of them are included in Ebm/ma7.
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 Ebm/ma7 chord. Feel free to save or share the image as needed.