Measuring the gullet is commonly misunderstood in all types of saddles, and it is easy to see if you take a browse looking for saddles online. There is no consistency anywhere. The only true way to know the gullet measurement is to take the information from the specifications that are set out by the manufacturer of the saddle.
The Figure Eight bridle gets its name from the noseband. It starts up by the cheek, crosses up and over the nose then down around and in front of the bit. It can also be called a Grackle, Mexican or simply a Crossed noseband. These types of nosebands are used to help prevent the horse from crossing their jaw. The center of this noseband can either be leather lined, or a sheepskin or fleece padding depending on the style.