F11 chord

The F dominant eleventh chord (abbreviated F11 chord) is a six-note chord consisting of the notes F, A, C, E♭, G, and B♭. The chord is formed by adding an eleventh to the F dominant ninth chord.

In practice, the third (A) and fifth (C) are often omitted from the F11 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.