Martingale Stop Donut

Used to stop the martingale rings from sliding too far forward and getting caught on the bit or on the buckles or studs that attach the reins to the bit.. Martingale stops can be rubber or leather stops slipped onto the rein between the bit and the ring of the martingale. They stop the martingale from sliding too far forward and getting caught on the bit or on the buckles that attach the reins to the bit. Sanctioning organizations require a running martingale to be used in conjunction with rein stops if the reins are buckled to the bit.