The sweet iron and copper link aids salivation and acceptance. Mouthpiece thickness: 16mm. Cheek height: 100mm. 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.