This indicator shows bars with large bodies (large expansion bars) as a red bar. They are important in the cd leg of a harmonic pattern, because they signal that extra confirmation is needed and that a failure of the PRZ is more likely.
The definition of this large expansion bar is a bar that has a body that is at least twice as big as the ATR with period 55.
This rule and indicator were originally created by Alexander Nikitin for MT4.