Rand Solar Powered Attic Gable Fan-20 Watt Wall/Roof Ventilator Panel NEW!! Cools up to 1813 square feet of attic space with its 1274 CFM capacity. High quality 20 Watt Polycrystaline Silicon Solar Panel Drastically cuts your cooling bill. Pays for itself in a VERY short time, all while being good for the environment. Includes free 85 degree thermostat, already prewired to the wiring harness. Solar panel includes adjustable angle bracket so you can dial in the optimal panel angle relative to the sun.