A bridoon is a small snaffle bit used as the upper mouthpiece in a double bridle; it has smaller rings and often a thinner mouthpiece so it sits comfortably above the curb and provides direct, non‑leverage rein aids to refine contact and impulsion. In combination, the bridoon offers subtle lateral and forward‑back communication while the curb applies poll and chin pressure for collection and head carriage.
Proper adjustment keeps the bridoon slightly in front of the curb so both bits act independently; correct sizing and dental checks are important because two bits share limited mouth space and can cause discomfort if ill‑fitted.