F# Major 7#11, 1st inversion (A# in the bass)
Also written as F#maj7#11/A#.
Notes, from the bass up
A# (bass)C#E#B#F#
The same notes as F# Major 7#11 (A#, C#, E#, B# and F#), rearranged so A# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.