The Herm Sprenger Duo D-ring Mullen Mouth Snaffle bit is an ideal option for horses who are not comfortable in traditional bits. Made of food-safe, solvent free, soft and flexible plastic reinforced with an inner steel cable, the Duo bit follows the shape of the horse's mouth better than traditional metal bits and is better accepted by many. The Duo has a different shape top and bottom and can be used right-side up or upside down to produce a different feeling in the horse's mouth. One side is a straight-edged flexible bar. The other side has an indentation to leave space for the horse's tongue.