This Dutch gag has a Waterford mouth made of many different links which makes it hard for the horse to take hold of and pull against it. The gag cheeks add leverage. This can be a severe bit. The 5" and smaller sizes of this bit come with shorter cheeks to ensure the bit remains in proportion with the smaller head. Mouthpiece thickness: 18mm. Cheek height: 150mm (4.5", 5"), 180mm (5.5", 6").