The Wonder Bit is an all-purpose versatile gag bit with a single-jointed mouthpiece. With rein use, the sliding mouthpiece moves forward to apply increased poll, palate, and bar pressure. This action can help to promote shoulder elevation, lateral flexion, and rate. Stainless steel. The addition of a curb chain to this bit can help increase speed, rating, and stop.The severity of a bit or hackamore is influenced by rein control of the rider and sensitivity of the horse. All riders should seek an equine professional that they trust when selecting a new bit, as every horse's needs are unique.