B sus2/C#
The B sus2 chord consists of the B (Perfect unison), C# (Major second) and F# (Perfect fifth) notes, with C# as the bass note.

How to play the B sus2/C# chord
- Play C# as the lowest bass note in the left hand
- Find B (Root) on the piano keyboard
- Add C# (Major second) — 2 semitones above B
- Add F# (Perfect fifth) — 7 semitones above B
- Press all 4 notes simultaneously to sound the B sus2/C# chord