piano chord
Fm7♭5
F1A♭♭3C♭♭5E♭♭7
A diminished triad with a minor seventh rather than a diminished one — half diminished, and not the same chord as dim7.
What is true of it
Fm7♭5 is F, A♭, C♭ and E♭ — 1, b3, b5 and b7 counted from F.
These are also the notes of A♭m6/F and G♯m6/F. Which name is right depends on what is underneath and what came before — the notes alone do not decide.