B Minor Major 9th, 2nd inversion (F# in the bass)
Also written as Bm(maj9)/F#.
Notes, from the bass up
F# (bass)A#C#BD
The same notes as B Minor Major 9th (F#, A#, C#, B and D), rearranged so F# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.