The Korsteel Copper and Steel Roller Full Cheek Snaffle 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. Full Cheeks keep this bit very stable in the horse's mouth and can aid in turning as they won't pull through. 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 and sometimes to contact the roof of the mouth.