Attaches quickly to the mast or boom on most small boats such as Lasers and Sunfish * Fits masts and boom ends from 1-1/2" to 2-1/2" diameter * Tough high impact plastic vane, designed to withstand years of punishment and abuse * Stainless steel mounting arm and set screw, as well as a tough plastic mounting base, add to the system"s durability * Wind vane length is 8"