A medium sized shackle weighs just 5 oz. with a 12,000 lbs. break strength. Good for the 30 to 45 foot boat. Standard Bails: The standard bail configuration provides ample room for attaching a line while keeping weight and overall shackle length to a minimum. Ideal for halyards and sheets. Large Bails: The bigger bails can provide room for up to three additional shackles or a combination of shackles and lines. Ideal for spinnaker sheets, guys or other multi-line applications.