Like all 19th c horse shoe brooches, it was designed to be worn w the branches of the horse shoe facing downwards. The Victorian/Edwardian belief was that the person wearing it should be showered in luck.
However, you can choose to wear it up or down, to suit your own tastes (or beliefs). This brooch is approx 1.25" x 1.25" and closes w a T bar hinged pin & a standard C clasp. This would look fabulous on a dressage stock.