Ab Quartal (So What), 4th inversion (D# in the bass)
Also written as Ab quartal/D#.
Notes, from the bass up
D# (bass)G#C#F#A#
The same notes as Ab Quartal (So What) (D#, G#, C#, F# and A#), rearranged so D# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.