The Bionaire Thin Window Fan with Comfort Control Thermostat disperses invigorating, revitalizing coolness for maximum comfort and freshness. Lifeless air dissipates to breaths of nourishing air and the renewing effects of cooler air become more present in your surroundings. It is more powerful with 40% greater air velocity compared to similar window fans and 25% more compact to reduce window obstruction. This fan also features three independently controlled comfort settings, adjustable thermostat and manually reversible airflow. It can be used either horizontally or vertically and has a "firm fit" locking extender screen. With Bionaire brand technology, you can live in harmony with nature for a serene home environment.