Kelly Silver Star SS Mini Wonder Bit The wonder bit is a versatile gag shank. The mouthpiece will apply more palate and bar pressure. Excellent all purpose mouthpiece. This bit is used on horses that pull through the bit or have learned to go beneath the bit. *Warning: this bit can be severe and cause a horse to bole, buck or rear over. Stainless steel. 3 1/2" or 4" mouthpiece.