Marinco Day/Night Solar Vent 4" - White [N20804W]Day Night Solar Vent 4" White The design threads into included deck plate, and is removable from the outside without tools. On off fan switches, LED lights, and intake exhaust switches are accessible from inside the cabin for ease of use. Features: Circulates fresh air in the boat cabin eliminating mold, mildew, and musty air Moves 1,000 cubic feet of air hour or 24,000 cubic feet of air day (4" model) A rechargeable battery allows for 24 hour