An order block that fails, gets swept through, and flips polarity once structure is reclaimed the other way.
Setup
Price rallies into a swing high.
SETUPFAILSSWEEPRECLAIMRETEST
It doesn't always look like this
Order block vs. breaker — an order block is drawn where a move started. A breaker is what's left after that order block fails and price reclaims structure the other way. Same-looking candle, different story.
The reclaim can take a while — the sweep and the structure break back the other way don't have to happen back to back; price can chop for several candles in between.
Works both directions — a bullish breaker comes from a failed bearish order block being reclaimed upward. A bearish breaker mirrors it: a failed bullish order block reclaimed downward.
Can fail again — a breaker isn't guaranteed either. If price closes back through it, it's just another failed zone.