The device secures and regulates a storm gib sail so the vessel is not out of balance when the mainsail has been reduced in storm conditions. It can be a life-saver and in fact an inner fore-stay with or without tensioner is compulsory for New Zealand yachts going blue-water (offshore or deep sea) sailing. The standard inner fore-stay tensioner until now has been the Highfield Lever, designed over 80 years ago with little modification. The Swageturn HookLever has fewer component parts, making it simpler, safer and more reliable. There was much less chance of losing any parts overboard because there was nothing to assemble or disassemble or connect on deck. The product is effectively a hook that is also a lever, with tension pre-set. Once hooked and locked with a recessed ring it would do everything it was required to do.
Hook Lever Installation instructions.