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

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