Full cheeks aid in turning the horse and help the bit to sit in a stable position in the horse's mouth. The full cheek can be used with or without bit keepers but will be more stable with the keepers. For safety, bit keepers are recommended as they secure the upper arm of the bit and can help prevent the cheeks from catching on fences, stirrups or other equipment should the horse scratch or bite at a fly.
The single jointed mouthpiece works by applying pressure to the bars, lips and sides of the tongue. As pressure is applied to the bit, the center joint collapses forward causing the bit to tighten in the horse's mouth.