The F sharp suspended fourth chord is a 3-note chord consisting of the notes F#, B and C#.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as F#sus4.
Chords that are a superset of F#sus4. The chords include more notes but always F#, B and C#.
Chords that are a subset of F#sus4. These contain less notes but all of them are included in F#sus4.
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 F#sus4 chord. Feel free to save or share the image as needed.