This mouthpiece is made of polished Sweet Iron which naturally oxidizes or rusts. Harmless to horses it has a sweet taste and promotes salivation. This is a very unique bit combination, great for the most steady and trustworthy horses who can handle the most tongue relief. The Myler 3-ring combination bit combines the features of a ring bit shank bit and hackamore to create a sophisticated training and riding tool. This bit features 3 ring cheekpieces and a 5 inch low medium wide ported barrel mouthpiece. Fully adjustable noseband/chin strap creates a unique bit versatile enough for any sport. Interfere less and communicate more with your horse.