The Dr Bristol bit has a flat link in the center of the mouthpiece. It is considered a 3-piece bit as it has two breaks and eliminates the “nutcracker” action of a single-joint bit. the mouthpiece lays across the tongue and, when the bit is at a certain angle in the horses mouth, the edge of the middle link will be in contact with the tongue. The Dr. Bristol is a great bit for horses that “brace” in a single joint bit.