The Eggbutt cheekpiece prevents pinching of the lips and gives a slightly more solid feel against the side of the face. It also prevents the bit from being pulled through the mouth. The release is slower and also introduces some poll pressure.

When the rein is used this mouthpiece wraps across the tongue creating tongue pressure and reducing bar pressure. Please note appearances may be deceiving, this bit joint is stronger than the Control Plate as pressure is more concentrated on the tongue.