Marine Boat 700CU FT Solar Powered 24 Hours Ventilator Rechargeable Battery Measuring 7 1/2" dia. and 3" H Two blades (exhaust and intake) are provided with each vent. It moves up to 700 cu.ft./hr of air during the day on solar power while charging a rechargeable battery to run at night. Ventilation can run on battery for 24 hours at full charge.