The Mikmar Jointed and Jointed Slanted mouthpiece is available in four sizes. They are 5” 5.25” 5.5” and 5.75”. They fit similar to any double-jointed mouthpiece, for example, French Link or Dr. Bristol. The 5” generally fits a horse with a smaller muzzle and mouth. The 5.25” fits most horses. The 5.5” and 5.75 are best for larger breeds for example, large Warmbloods or Draft crosses.