Combines poll pressure and leverage for a mild gag action. Brass alloy assists with salivation. Mouthpiece thickness: 14mm. Cheek height: 115mm (4.5", 5"), 130mm (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.