The Bow Shackle Nut Bolt is a more secure version used in rigging that features the combination of a bolt and nut located alongside a cotter pin. Bolt type shackles can be used in any application that uses a round pin or a screw pin. These types of shackles remain secure even when the shackle is subjected to rotation or torque. Shackle is an 'O' shaped metal link which is closed by a bolt. Similar to an Anchor Shackle, the rounded design of Bow Shackle Nut Bolt allows Bow Shackles to take loads from many directions.