Billy Royal Pro Correction Horse Bit with Silver Dots Square Mouth is the perfect tool for fine tuning retraining older broke horses or for advanced level horses. It features a unique hinged square port with roller that allows pressure to be applied evenly across the palate. The bit includes a copper inlay on the mouthpiece that promotes salivation and increases sensitivity. The antique bronze swivel cheeks with silver dot detail provide a beautiful balance. The design of this bit allows each side of the horse to be worked individually for flexing and bending exercises. Measures: Mouthpiece: 5 Cheeks: 7 3/4 Port: 1 Bit diameter: 3/8.