The D flat suspended fourth seventh chord is a 4-note chord consisting of the notes Db, Gb, Ab and Cb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Db7sus4.
Chords that are a superset of Db7sus4. The chords include more notes but always Db, Gb, Ab and Cb.
Chords that are a subset of Db7sus4. These contain less notes but all of them are included in Db7sus4.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Db7sus4 chord. Feel free to save or share the image as needed.