F# 7sus2, 2nd inversion (C# in the bass)
Also written as F#7sus2/C#.
Notes, from the bass up
C# (bass)EF#G#
The same notes as F# 7sus2 (C#, E, F# and G#), rearranged so C# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.