This Black Max wind direction indicator attached quickly to masts and booms on most small sailboats. Unique mounting system fits masts or booms from 1.5 to 2.5 inches. Made from tough high impact plastic, this wind indicator was designed to withstand years of punishment. This kit includes the wind vane, stainless steel mounting arm and a tough plastic mounting base. The wind indicator is 8" long and comes in its own storage tube.