Fan-Tastic RV Roof Vent with 12V Fan & Thermostat - Manual Lift THREE-SPEED FAN - This lightweight, compact and durable vent fan seals tight when not in use. Powerful 12 in, 10-blade fan quickly moves air in and out of the cabin. The core of this truly fantastic ventilation solution is a high performance rotary fan that features three blade speeds; low, medium, and high ACHIEVE THE IDEAL ON-BOARD TEMPERATURE  For true comfort at your convenience, the Fantastic Vent has a built-in thermostat to take care of maintaining your desired temperature REVERSIBLE AIRFLOW - The powerful yet compact Dometic Fantastic Vent has fixed, manual speeds or automatic variable speeds to get the airflow precisely as you want. It's simple reverse switch changes the fan direction, drawing air in or out of the vehicle NO NOISE - Warm and stale air out, fresh and clean air in. Dometic FanTastic Vent does it in a matter of minutes. Its pleasantly quiet and energy saving, too PERFECT FIT - Fits standard 14 inch x 14 inch openings. White, high profile base and smoke dome. Lifting knob to open manually.