A Hackamore works by pressure on the nose by means of a leverage. The pressure on the nose depends on the length of the shanks. A hackamore is in principle a tool for bitless riding, but can also be used in combination with a bit.
A hackamore can be quite sharp due to the leverage of the shanks and the action of the curb strap. If a chain is used here, the hackamore is much sharper.
It is very important that the hackamore is in the right place on the nose.
The hackamore is not suitable for inexperienced rider or horse.