Made of plastic, 76.2 mm (3") connection, 138 lt (700 cu ft) air volume. Two functions, air intake and air exhaust. No wiring required. The model with the rechargeable battery can operate for up to 30 hours without receiving solar radiation. EVAL's solar ventilator refreshes the air in the space by utilizing solar energy. The photovoltaic system located on the top of the duct activates the fan and achieves high-performance ventilation.