Stainless Steel 3-Ring Combination Bit - 6" Shank with Sweet Iron Correctional Ported Barrel (MB 41PB) Copper Inlay Mouth. This mouthpiece is made of polished Sweet Iron which naturally oxidizes. How it works: the 3-ring combination bit uses five different pressure points to disperse rein pressure. The noseband and chin strap are connected through the purchase; when the reins are engaged, the horse first feels the nose, chin and poll pressure before he feels the mouthpiece. The mouthpiece can slide 1" before reaching the stop, where it will engage. The overall effect is to give the horse several opportunities to respond to the rider’s rein signals, plus disperse the rein pressure over multiple pressure points rather than just the tongue or bars. Select the rein position most suitable for your hands. About the mouthpiece: the 41PB is a truly unique Myler mouthpiece. This mouth piece is a correctional mouthpiece, a ported mouthpiece that collapses on to the outer lip and bars, and rotates on to the tongue. The port has a staggered or tiered design. The base of the port is generously wide with rounded corners, offering virtually the same comfort and tongue relief of a Level Tree mouthpiece. The top of the port is narrower and has pronounced corners. If the horse is relaxed, the tongue can pass comfortably under the wider opening. When the reins are engaged, the mouthpiece collapses on to the bars and lips and rotates on to the tongue (similarly to the 27PB, but to a lesser degree). The pronounced corners of the port apply two points of pressure on the tongue for increased control. The result is a mouthpiece that offers maximum tongue relief for the horse, but very good control for the rider. The unique design and the generous tongue relief of the 41PB make it the only correctional that can be used long term, possibly even as a horse’s finishing bit. The 41PB used with Western cheekpieces is 1 ¼" high.