The F lydian dominant seventh chord is a 5-note chord consisting of the notes F, A, C, Eb and B.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as F7#11.
Chords that are a subset of F7#11. These contain less notes but all of them are included in F7#11.
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 F7#11 chord. Feel free to save or share the image as needed.