Eggbutt single jointed hard carbon

: Single jointed bits transmit the rider's aids to the edges of the tongue, and to the bars. When giving a rein action, the bit forms a V and exerts this pressure. This can be described as a "nutcracker" action. Single snaffle bits are not recommended for horses with a flat palate or small mouth cavity. They are best used on horses with a hollow palate and no sensitive bars or tongue. 

Fixed eggbutt, verdun or full cheek rings transmit rein tension directly to the tongue and lower jaw, with no leverage on the nape of the neck. The action is more direct, and also acts laterally. The larger the ring, the greater the lateral action. Fixed rings provide greater comfort at the corners of the mouth, with no risk of pinching. They are recommended for horses that are unstable, have sensitive commissures, or may be a little heavy on the hand.