Acavallo Opera Young Fetlock Boots Classic GelAcavallo fetlock boots in polyurethane, with neoprene and gel lining. Hook and loop closure. The Opera Young fetlock boots for young horses are the perfect choice for competing in various categories, including young horse categories compliant with FEI or FN regulations, as well as in open categories and other equestrian disciplines. These protections, like all Avacallo ideas for horses, follow an anatomical line, so as to guarantee a comfortable and