Reefing Hooks are a quick, clean and simple way to secure the tack of your mainsail for reefing. Bolts to the gooseneck or boom. The only piece of hardware needed for the tack reef point. Hole dia.: 1/4". Can either be screwed to the Boom or are attached to the horizontal gooseneck pin.Key FeaturesKeep the sail pivot point in line with the boom pivot point316 stainless steel for extra corrosion resistanceMakes sails easier to trim and handleReef hooks for safety in heavy weatherChoose from 5/16" diameter rod, with an overall length of 3 1/2", or a larger 3/8" diameter model that is 4 5/32" in length