Gag bit

It is considered a severe bit used to provide more braking power.

The gag bit works on the horse's lips and poll simultaneously.

Gag bits are most commonly seen in polo, eventing (especially for cross-country), show jumping, and hacking, mainly for increased control at times where a horse may be excited or try to run off with the rider.

Additionally, the horse is supposed to be completely submissive in dressage, and a gag bit gives the impression that it is not.

Gags are also never seen in the hunter arena, again because riders wish to portray that the horse is an easy ride, and because the ideal is a long, relaxed frame with the neck stretched out, rather than a high neck.