Details:
Powerful 10-speed intake and exhaust fanThermostat to control room temperatureProvides over 900 CFM to keep you cool and comfortableFits all standard 14" x 14" roof openings. Open and close the vent lid by simply rotating the knob, push the knob up to lock in placeElectric lid opening with remote control
DIY kit: Comes with custom install ring for forward raised circle.  Installation ring creates a template for the roof cutout and is used to sandwich the fan to the interior skin of the van.