D 5/Eb
The D 5 chord consists of the D (Perfect unison) and A (Perfect fifth) notes, with Eb as the bass note.

How to play the D 5/Eb chord
- Play Eb as the lowest bass note in the left hand
- Find D (Root) on the piano keyboard
- Add A (Perfect fifth) — 7 semitones above D
- Press all 3 notes simultaneously to sound the D 5/Eb chord