For horses that are sensitive or have an injury in the mouth leather bits are frequently used. The long shanks on the hackamore will provide significant poll pressure when needed while working in conjunction with pressure across the nose to ensure aids through the reins are light but effective. Leather is very palatable and easily accepted by the horse, promoting salivation and comfort inside the mouth. This bit could be a moderate to severe bit depending on its assembly. 
Note: The bit must be fitted so that the seam faces the mouth opening. As it is a soft material, traces of use may occur due to the horse's teeth. These do not represent a quality defect.