D 7alt, 3rd inversion (Eb in the bass)
Also written as D7alt/Eb.
Notes, from the bass up
Eb (bass)E#BbDF#C
The same notes as D 7alt (Eb, E#, Bb, D, F# and C), rearranged so Eb is the lowest note. Use it to move between chords with smaller jumps across the keyboard.