The C sharp altered chord is a 4-note chord consisting of the notes C#, E#, B and D.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as C#alt7.
Chords that are a superset of C#alt7. The chords include more notes but always C#, E#, B and D.
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 C#alt7 chord. Feel free to save or share the image as needed.