Nicro Day/Night Plus 3 inch Day/Night Vent with Stainless Steel cover. 24-Hour Solar Powered Ventilation. Circulates fresh air in boat cabin. Protects against mold, mildew and musty air. Now with even more power, the Nicro Day/Night Plus moves over 800 cubic feet of air in an hour or 19200 cubic feet of air a day (3 inch model). With direct to deck installation it easily replaces any existing 3 inch NICRO vent product. The Day/Night Plus has complete air and green water shut-off from below, as well as a built-in on/off fan switch. Rechargeable battery allows for 24-hour continuous operation. No wiring required. Easily replaces any existing 3 inch NICRO vent. High capacity NiMh battery operates vent for up to 40 hours without sunlight. Direct to deck installation. All mounting hardware, interior trim ring, and insect screen included. 2 year limited warranty. Interchangeable intake and exhaust fans. Whisper quiet fan operation. Vent Diameter: 3 inches. Cutout Diameter: 3-3/4 inches.