A hackamore is a special mouthpiece that has no bit. The horse's mouth is completely free. It consists of a noseband and a curb chain which work by pressure points on the horse's head, on the muzzle and on the chin. A hackamore is used on opposite reins (support reins). It has a very powerful leverage effect depending on the size of its branches: its severity comes from the support on the fragile bones of the muzzle, and under the lower jaw, of a more or less "hard" curb chain (in leather, or in metal chain) which tightens this sensitive part of the horse's head. It is now seen on show jumping grounds, sometimes as a double of a simple bit in order to combine the two actions. In any case, it requires a light and experienced hand.