Cmaj11 chord

The C major eleventh chord (abbreviated "Cmaj11 chord") is a six-note chord consisting of the notes C, E, G, B, D, and F. The chord is formed by adding an eleventh to a C major ninth chord.

In practice, the fifth (G) is often omitted from the Cmaj11 chord to avoid a very dissonant sound, and because it's not always possible to play all notes simultaneously.