This loose ring EquiKind+ snaffle offers more movement in the horse's mouth and helps to discourage leaning on the bit. Mouthpiece thickness: 15mm. Cheek height: 50mm (4.5"), 65mm (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.