This Dutch gag has a Waterford mouth made of many different links which makes it difficult for the horse to take a hold. The gag cheeks add leverage. This bit should be used under supervision or by an experienced rider. Mouthpiece thickness: 18mm. Cheek height: 145mm (4.5", 5"), 180mm (5.5", 6"). Brass alloy mouth: Copper is alloyed with a harder metal to produce warm, durable mouthpieces which aid salivation. Stainless steel is used for the cheeks due to it being durable, easy to clean and resistance to rust.