Green alternative to exhaust fans, GreenRoo provides 5,000–10,000 cfm of airflow without use of electricity. Wind-driven ventilator has maintenance-free design, incurs no electrical installation or operating costs, and incorporates Varipitch component to make it usable on any roof slope. Made of aluminum and SS, product can be powder-coated and comes in throat diameter sizes of 12, 24, and 36 in., all weighing less than 70 lb.