The SMB II is the best-selling equine leg care product in the world. They have protected countless performance horses over the years in every imaginable event, including polo, jumping, reining, barrel racing, endurance, working cow horses, and many others. For many horses, these boots have meant the difference between an extended career and periodic or permanent injuries. So, it's no wonder there have been numerous attempts to copy them. This boot is designed for use on either the front or the hind legs. Sold in pairs.