Best friend grazing muzzles are recommended by equine health professionals to prevent, as well as treat, laminitis, founder, The small opening in the bottom allows horses a limited amount of grass, yet unlimited water. Rather than being restricted to Best friend muzzles are guaranteed to be the highest quality muzzles on the market. Size is Horse. Dimensions are 0.667 X 0.667 X 0.667 Rubber Nylon Plastic. UPC Code = 754888042712