Drop 2 III

The Drop 2 III voicing of Fb7#5 stacks Fb, C, Ebb and Ab from the bottom up: the root, sharp 5th, minor 7th and major 3rd of the chord.

It's one of the Drop 2 voicings: four-note chords in close position with the second note from the top dropped an octave, played over the root. The others for Fb7#5 are Drop 2 I, Drop 2 II and Drop 2 IV.