The Boat Vent II mooring pole vent keeps air circulating under boat covers in order to prevent moisture buildup and mildew. Our vents are easily attached to the cover by cutting a small hole in the canvas and screwing the top of the vent to the bottom. No tools are required. Our vents are easily attached to our mooring poles using the ¾” tube end instead of the pole tip in the upright position. The bottom of the vent will also accommodate ⅞” tubing. When the cover is not in use, the mooring pole pulls out of the vent for easy storage.