THE American gag is a snaffle-type bit, with upper shanks to which the cheekpieces attach, and lower shanks with attachments for the reins. It can also be used with a second set of reins connecting to the metal loops at the end of the mouthpiece, giving a milder action.

IT has a leverage (elevator) action, although it is not classed as a true leverage bit because there is no curb chain. Pressure on the gag rein causes the bit to pull on the cheekpieces, which raises the bit and exerts pressure on the poll and corners of the mouth. It gives the horse a firm message to get his head up and stop, so is useful for a strong puller or a horse that leans on the hand. It's a great help with turning and brakes, but can encourage a high, stiff neck carriage.