Seldén Double Snap/Lead Shackle 60 (307-440-10) is a rigging and deck-hardware connector for joining compatible blocks, eyes or control-system components. Double Halyard Swivel Shackle. For hauling out a jib sheet off the wind, and other temporary line routing. Choose the fitting by pin diameter, internal width, working load and articulation required at the connection. When replacing an existing shackle or toggle, compare the dimensions and article number rather than relying on appearance alone. The connected fittings should be free to align with the load without binding, and the pin or retaining arrangement should be secured in accordance with the original installation.