Shires Bevel Bit with Jointed Mouth. Shires Bevel Bit, also commonly known as the Wilkie bit, applies added pressure to the poll as the rings cause the bit to be raised in the horse\\\'s mouth when rein pressure is applied. The Bevel Bit is ideal if extra brakes are needed and is a popular bit used in the show ring. The Shires Bevel Bit with Jointed Mouth is a single jointed bit with a nutcracker action that works on the tongue, the bars of the mouth and can have action on the horses palate.