Pure copper is a soft, warm metal. By using 99.9% pure copper in the center of the mouthpiece, bit acceptance is improved. The taste of copper encourages horses to salivate and keep a moist mouth. Bits made of copper can have a very positive effect by promoting relaxation and softening. Excellent bit acceptance can be achieved by this combination of Apple scented space age polymer mouthpiece and pure copper center roller. The Happy Mouth® Pro King Dee Bits feature a more traditional-looking Dee Ring cheek which is more desirable in the hunter and equitation arenas. Note that due to the construction on the cheek, this bit style will measure 1/4″ less than the listed sizes state.