Camper Roof Vent Fan-By Fan-Tastic Vent-Model 6000 RBTA-W/Thermostat & Dome Sensor Fan-Tastic RV Roof Vent Model 6000's dome cover is opened when the dome up switch is turned on and closed when the down feature is selected. Polycarbonate dome will close when the rain sensor becomes wet, then re-opens once the sensor dries. A built in manual knob allows you to close the dome in an emergency, adjust the opening to a desired position, or to over ride the Rain Sensor. Fits standard 14" x 14" roof openings. 16-1/2"L x 16-1/2"W x 14-1/2"D. 2 year warranty. 1 per box.   Air vents are activated when the three-speed switch is turned to any of the three speed selections. The dome cover is opened when the dome up switch is activated and closed when the down feature of the switch is selected. To activate the fan blade, the built-in thermostat must be turned to a temperature selection, which is lower (cooler) than the current interior temperature. Once the selected temperature is attained, the fan blade will shut off, but the dome will remain open until the down feature is selected or the built-in rain sensor becomes wet. Once the sensor dries, the dome will re-open. For storage, the dome switch must be in the down position and the three-speed switch in the off ("O") position. Fan-Tastic RV Roof Air Vents - Technical Information€¢ Durable, proven longevity€¢ Quiet, 12 €“volt ceiling fan with 3-speeds€¢ Dome-polycarbonate/Lifetime warranty€¢ Removable screen for easy cleaning€¢ Reversible fan blade motor (in or out)€¢ Low AMP draw insures full-time use Air Vents - Specifications€¢ Rooftop weight 10 to 14lbs.€¢ Dimensions 16 1/2 x 16 1/2 x 141/2 Fan-Tastic Camper Air Vent Fans have a two-year limited warranty (lifetime warranty on exterior dome) against defects in materials and workmanship when installed and operated according to instructions