A 3-ring bit is best known as a Pessoa bit. A 3-ring bit consists of a snaffle with an extra ring at the top and one or two rings at the bottom. The upper ring is used to attached the snaffle to the bridle.
A 3-ring bit can be used with one or two reins and the reins may be attached to any of the rings. The further the reins are placed apart, the stronger the bit will be. When the rider wants to ride with just one rein, he can also use a pelham strap. The 3-ring bit can also be used with a curb chain.
By placing the reins down, the leverage is gets bigger. The horse gets pressure behind the ears and the bit slides up in the horses mouth.
This bit is not suitable for inexperienced riders and horses, however it is suitable for strong horses.