3/8" Smooth Sweet Iron Dog Bone Snaffle with Copper Roller. 6" Cheeks, 5" Mouth. One of the most popular shanks for training when leaving the ring snaffle. Great for introducing curb pressure. This mouthpiece bends over the bars at a greater angle than a solid or two piece mouthpiece, allowing contact to new nerves for better control. Copper roller can help calm a nervous horse and adds some light tongue pressure for better headset.