The quick-release snap shackle differs from other snap shackles. It fulfills the same functions, but can be released rapidly, even under tension.
The quick-release snap shackle is particularly suited to foredeck sail maneuvers (spinnaker, genoa, jibs, etc.). It is used on halyards as well as sheets.
There are two types of quick-release snap shackle. Some have a release pin that is pulled by means of a small split ring or lanyard. Others open by finger pressure. When overloaded, a pin breaks, releasing the shackle.
The size of the quick release shackle will be determined by the diameter of the clew grommet and the expected load.