Boat Vent II™ is an easy to install boat cover vent that brings air circulation to your enclosed boat to prevent the buildup of warm, moist air. This boat cover vent will prolong the life of your boat's upholstery by helping to prevent the growth of mold, mildew and bacteria that can come from moist, stagnant air under your cover. Use the Boat Vent II in conjunction with the Cam-Lock Support Poles (sold separately) to create proper tenting that will shed rain or snow off the top of your cover and prevent pooling.