The Fulmer cheek piece will prevent pinching on the sides of the mouth, and the extended pins above and below the bit, firstly prevent the bit being pulled through the mouth and secondly aid guiding the horse's head which is great for schooling purposes. As with the Eggbutt, the release is slower than the loose ring and also introduces light poll pressure.
The Mullen distributes pressure evenly over all the structures of the mouth, while this avoids pressure points, it does make the Mullen a fairly strong bit. The material used allows the bit to remain light and it encourages salivation. It is particularly well suited to horses that object to metal mouth pieces.