Online for Equine offer the Shires Silicone Reins Stops.

Rein stoppers are used to prevent the running section of the martingale from slipping down toward the bit preventing excessive movement in your martingale, helping to ensure that the martingale comes into action correctly.

The silicone design makes these rein stops a little easier to apply when compared to rubber.

The Shires Silicone Reins Stops are supplied in pairs and are available in black or brown.