Exact formation
Two candles with practically the same highs; A bullish one usually appears followed by a bearish one.
What is happening in the market
Demand tries to overcome the zone twice and finds enough supply to stop it.
Where it matters
After a climb and in resistance.
How to confirm it
Break of the low of the second candle or of the set.
When it is invalidated
Firm close on shared highs.
Common mistake
Use it within a narrow range where similar highs are common.