Mustang Cowboy String Running Martingale Mustang Cowboy String Running Martingale is designed for durability. This simple, yet effective tool is perfect for developing young horses and maintaining finished ones. Helps with accuracy and precision in developing light mouths. White poly string martingale has nickel plated rings and bolt snap cinch connector. Adjustable neck string secures the forks by running through the gullet and over the saddle horn. Features: Durable Helps develop light mouths Adjustable neck string Item Specifications: Material: Poly string