May help some horses to better relax their jaws and be more accepting of contact. Copper increases salivation which encourages the horse to swallow more and to chew the bit. Both the chewing and swallowing actions can help to relax the jaw and promote better bit acceptance. Eggbutt cheeks keep this bit stable in the horse's mouth.
The single jointed mouthpiece works by applying pressure to the bars, lips and sides of the tongue. As pressure is applied to the bit, the center joint collapses forward causing the bit to tighten in the horse's mouth.