D# sus4/B
The D# sus4 chord consists of the D# (Perfect unison), G# (Perfect fourth) and A# (Perfect fifth) notes, with B as the bass note.

How to play the D# sus4/B chord
- Play B as the lowest bass note in the left hand
- Find D# (Root) on the piano keyboard
- Add G# (Perfect fourth) — 5 semitones above D#
- Add A# (Perfect fifth) — 7 semitones above D#
- Press all 4 notes simultaneously to sound the D# sus4/B chord