The F-flat power chord (abbreviated "Fb5 chord") is a two-note chord consisting of the notes F♭ and C♭. The chord is formed by removing the major third from a F-flat major chord.
F-flat power chord
F-flat fifth chord
F♭omit3 F♭(omit3) F♭no3 F♭(no3)
dyad (two-note chord)