The MB 04 is similar to the MB 02 in that it will rotate on the tongue and apply tongue pressure, however, it has a small (¼") port that introduces some tongue relief to the horse. The port allows the horse to swallow and move his tongue when he is moving forward and relaxed, which acts as a release or reward. The mouthpiece is curved, and it wraps around the bars and lips instead of pinching. Mouthpiece is 14mm at the cheek.
Notes: The MB 04 provides an excellent transition from Level One to Level Two. It is suitable for a wide range of horses including green horses, experienced horses entering the Myler System, horses that have been ridden exclusively in a single-jointed mouthpiece, or horses that have not been ridden for a while needing re-schooling.
The loose ring is a simple stainless steel "O" shape where both the bridle and mouthpiece have no fixed point of attachment but slide freely around the ring. The loose ring allows a lot of play as the mouthpiece slides freely around the ring.
Notes: The loose ring is generally considered one of the most non-interfering cheek pieces because the mouthpiece slides freely around the ring. However the play in the mouthpiece can make it difficult for a horse to find your hands as the mouthpiece is in continual motion. The movement of the mouthpiece can also exaggerate or create a busy mouth in young or anxious horses. It is best suited for more advanced horses fully schooled in leg and seat aids as well as rein aids.