Ab Quartal (So What), 2nd inversion (F# in the bass)
Also written as Ab quartal/F#.
Notes, from the bass up
F# (bass)A#D#G#C#
The same notes as Ab Quartal (So What) (F#, A#, D#, G# and C#), rearranged so F# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.