The Williams cheek piece allows for multiple rein positions. If connected to the main ring the bit acts as a loose ring, but when connected to the bottom ring it promotes pole flexion by creating more positive poll pressure. The Williams cheek piece helps to prevent drifting.
Our Snaffle is a popular bit due to the curved mouthpiece which distributes pressure more evenly over tongue and bars. With the offset center link it will reduce the nutcracker action and pressure points on the tongue.