Ab Quartal (So What), 3rd inversion (A# in the bass)
Also written as Ab quartal/A#.
Notes, from the bass up
A# (bass)D#G#C#F#
The same notes as Ab Quartal (So What) (A#, D#, G#, C# and F#), rearranged so A# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.