Snaffle bits are one of the basic bits use to train young horses.  It consist of one bar, called a Mullen mouth  bit or two bars linked in the middle. The rings at each end attach to the reins. The rings may pass through the mouth piece which  is called a ring Snaffle bit or it may be made  in the Eggbutt style. Snaffle bits may be  used in English riding or Western riding . Some snaffle bits have other features such as rollers. These rollers may be of copper, stainless steel or other materials. The point is to keep the horses mouth moist.