Gatsby (R) Flat Standing Martingale Beautifully crafted from supple, pre-conditioned leather, this flat standing martingale features stamped steel hardware. Features: Supple, pre-conditioned leather Stamped steel hardware Color: Havana Gatsby(R) Your Horse, Our Purpose. Founded in 1979, Gatsby(R) is one of the industry's most recognizable and credible equestrian brands. They are founded on the belief that the more time you spend with your horse, the better - that's why the products designed by Gatsby(R) make sense for the barn and for your budget.