piano chord
E♭sus4
E♭1A♭4B♭5
The third replaced by the fourth, which leans on the third it is standing in for.
Written the other way round it is D♯sus4 — the same twelve keys on a piano, a different piece of notation.
What is true of it
E♭sus4 is E♭, A♭ and B♭ — 1, 4 and 5 counted from E♭.
These are also the notes of A♭sus2/E♭ and G♯sus2/E♭. Which name is right depends on what is underneath and what came before — the notes alone do not decide.