The bib martingale attachment is similar to a running martingale but has a solid central piece of leather instead of two running straps.

The bib stops the horse from raising his head too high, keeps the reins closer together and helps to prevent the reins from coming over the horse's head.

The bib also prevents the problem of straps flapping around, which may distract the horse. It also deters the horse from trying to catch the martingale in his mouth and chew on it, thus risking injury.