3.25” cheek, 5” mouth. The Mullen mouth with copper wrapped bars in combination with the rope noseband helps to get your horse’s nose and round out the turn. The copper mouthpiece keeps the mouth moist which makes the horse more willing to be trained. It is a favorite of many timed event fixers because it is such a proven winner. Use this bit for training a young horse or the competition horse that’s already patterned.