Ab 7alt, 2nd inversion (F# in the bass)
Also written as Ab7alt/F#.
Notes, from the bass up
F# (bass)ABEG#B#
The same notes as Ab 7alt (F#, A, B, E, G# and B#), rearranged so F# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.