This fan is designed to be used with Whirly Bird Roof Mount it works with both Solar Power Attic Ventilator and Wind. So even at night when sun is not shinning, if there is wind it will still remove the heat from the attic in summer and helps prevent moisture and ice dams in the winter without using any electricity. Keeping your attic cool and dry. can extend the life of your roof, by preventing rot, premature aging and damaging shingle distortion that can be caused by excessive heat. This energy saving solar powered attic ventilator also reduces energy costs by reducing running time of air conditioners. Easy retrofit can easily replace standard powered attic ventilators. Solar Powered Attic Ventilators operate without fuel, or pollution. Saves money on electricity. Comes with a 50 watt solar panel, a 12 inch plastic fan, a high efficiency fan blade,15 feet of wire and 4 Z brackets. The dimensions for the fan are 12"x12"x3" made to be installed inside of a whirly bird.(whirly bird sold separately).