The sweet iron and copper combination used in this training bit provides a warmth for the horse which encourages salivation and gives a pleasant taste. Mouthpiece thickness: 12mm. Cheek height: 65mm. Sweet iron mouthpieces are designed to oxidize to produce a sweet taste which helps with mouthing. The addition of copper to the mouth ensures the horse will not take up too much of a contact, ideal for horses that can take a hold. Stainless steel is used for the cheeks due to it being durable, easy to clean and resistance to rust.