 [tack]
[tack]  A fiador ɔr term of Spanish colonial origin referring to a hackamore component used principally in the Americas. In English-speaking North America, the fiador is known principally as a type of throatlatch used on the bosal-style hackamore. Its purpose is to stabilize a heavy noseband or bosal and prevent the bridle from shifting. It...
Found on 
http://en.wikipedia.org/wiki/Fiador_(tack)

Knotted rope throatlatch, used in conjunction with a basal, browband headstall, and horsehair reins The knots of the fiador are the hackamore, the fiador, and the sheet bend
Found on 
http://www.gaitedhorses.net/Articles/HorseGlossary.html
  No exact match found.