The sweet iron and copper combination in this tom thumb bit help to promote salivation and encourage softening. The cheeks give this bit a lever action. The raised copper rollers can help to prevent the horse taking too much of a hold. Mouthpiece thickness: 14mm. Cheek height: 140mm. 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.