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