The C-flat dominant seventh flat five chord (abbreviated "Cb7(b5) chord") is a four-note chord consisting of the notes C♭, E♭, G♭♭, and B♭♭. The chord is formed by lowering the fifth of a C-flat dominant seventh chord a half step.
C-flat dominant seventh flat five chord
C♭ E♭ G♭♭ B♭♭
1 3 ♭5 ♭7
Tetrad (four-note chord)