Fastening devices and systems and methods thereof. Fastening devices and systems and methods thereof can include a unitary or one-piece body having first and second ends configured and operative to be coupled together or to be coupled to their respective complement in another of said fastening devices. The first end can include a ring or annular portion and a projection that are sized and shaped to fit around an anchor and in an orifice, respectively, of the second end. Fastening devices and systems and methods thereof according to embodiments may be used with items, including footwear, apparel, luggage, a backpack, a bag, a purse, a boxing glove, a punching bag, football or lacrosse shoulder pads, or the like.