One of the most popular shanks for training when leaving the ring snaffle and applying some curb pressure. The mouthpiece bends over the bars at a greater angle than a solid or two-piece mouthpiece, allowing contact to new nerves for better control. The copper roller can help calm a nervous horse and add some light tongue pressure for a better head set. Sweet iron is intended to rust and promotes salivation for a supple feeling mouth. The mullen relief mouthpiece creates even pressure across the bars and tongue to eliminate nutcracker effect. Moving from Direct Reining to Neck Reining? The stage b is all about transition, with the introduction of leverage and curb pressure.