This Jointed Rubber Mouth Eggbutt Bit is stationary in the mouth, as the mouthpiece does not rotate around the ring and it prevents pinching of the lips.  The copper also keeps the horses mouth moist. The Equine Jointed Bit also provides snapping action with rings and mouthpieces.  This item measures 2" in rings and 14mm mouth. This item is available in 5" size.