The EquiKind+ peanut link helps to encourage a softer contact. Eggbutt rings are ideal for horses with sensitive lips. Mouthpiece thickness: 15mm. Cheek height: 55mm (4.5"), 75mm (5", 5.5"). The EquiKind+ coating is thinner than a rubber mouthpiece making them more comfortable for horses that don't have room for a thick mouthpiece and ideal for sensitive mouths or horses that don't like metal in their mouths. Stainless steel is used due to it being durable, easy to clean and resistance to rust.