The Loop Ring Lozenge Link Snaffle (also known as a Wilkie Bit) can be used to allow the rider to gain extra control.
This bit can be used as an ordinary snaffle, or the cheek pieces can be attached to the top loop to increase poll and lip pressure. When pressure is applied to the rein, the action on the cheek pieces promotes pressure on the poll to bring the head down. To further increase this, the reins can be attached to the lower loop.
A popular bit for when extra brakes are needed
Offers a mild level of poll pressure